Saturday, August 9, 2008
White Cloud in Blue Sky
Hovering white clouds all around the cities of THIMPU and PARO of Bhutan..........specially when the whether remain clear and shiny...............The sky seems to be very close and as if you can touch it when ever you want to touch it......................
Making Photographs:07
a textbook by Philip Greenspun; revised January 2007
(after last publication)
Panoramic Cameras
Any camera can be a panoramic camera. You need only take a negative to a professional laboratory and say "make me a long skinny print from this portion of the negative". Or take a negative to any lab and say "make me a big print from this negative". Once you get home, use a pair of scissors to trim the big print until it is long and skinny and contains the subject matter of interest. This may sound absurd but it is in fact how most 35mm "panoramic mode" cameras operate. They use the same lens as in normal mode and mask off the top and bottom of the frame. Then the laboratory knows that you wanted a long skinny print and it is obvious which portion of the neg to print (i.e., the non-blank portion). APS cameras do the same thing except that they record the panorama mode magnetically on the back of the film. The entire frame is exposed and you could later change your mind and ask the lab to print the whole frame.
You won't get very high image quality if you print from only a tiny portion of a tiny negative. But that doesn't mean you need a true panoramic camera. You could just use a big view camera and bring the resulting 4x5, 5x7, or 8x10 sheet of film into a pro lab and tell them to print only the central portion.
If that seems like a waste of film and effort, then the Fuji 617 that I own is for you. Fuji takes one of their 5x7 view camera lenses and attaches it to a body that handles 120 and 220 roll film. So the photographer is freed from the bulk of the 5x7 view camera, from the drudgery of loading sheet film into film holders, and from having to spend $6 per exposure on film and processing (instead it is perhaps $3 per exposure).
Panoramic cameras don't have the perspective correction flexibility of the view camera from which they were cut down. This is very annoying if you're trying to capture architecture in a city. Panoramic cameras don't have the close-focus capability of view cameras. This is annoying if you want to include a person's face prominently in your image. Panoramic cameras can be unbelievably expensive compared to the view cameras from which they are derived. For example, Linhof makes a 617 camera similar to my Fuji. A Schneider 72mm lens for the camera is $4000. The same lens ready for use on any view camera was $1500 (in December 1998).
There are panoramic cameras that do things you could never do with a view camera and cropping. These have rotating lenses that capture up to 360 degrees onto long strips of film, e.g., the $650 Spinshot camera makes 7 frames on a 36-exposure roll of 35mm film. The Noblex is the standard rotating-lens 120 roll-film camera. It captures 150 degrees on a 6x12 frame.
I'm not really an expert on panoramic photography but I think that the main advantage of the fixed lens camera is simplicity. A camera with a rotating lens can produce very strange results if the lens does not rotate smoothly. The big advantage for the rotating lens cameras, in addition to wide field of view, is that they are free of the edge distortion and light falloff that you get with wide angle lenses.
One thing to keep in mind is that if your panoramic camera produces an image that does not fit into a 4x5 enlarger, you won't be able to print images yourself in a darkroom and will be forced to used a professional laboratory where they have an 8x10 enlarger. Note that 6x12 fits in a 4x5 enlarger but 6x17 does not.
(after last publication)
Panoramic Cameras
Any camera can be a panoramic camera. You need only take a negative to a professional laboratory and say "make me a long skinny print from this portion of the negative". Or take a negative to any lab and say "make me a big print from this negative". Once you get home, use a pair of scissors to trim the big print until it is long and skinny and contains the subject matter of interest. This may sound absurd but it is in fact how most 35mm "panoramic mode" cameras operate. They use the same lens as in normal mode and mask off the top and bottom of the frame. Then the laboratory knows that you wanted a long skinny print and it is obvious which portion of the neg to print (i.e., the non-blank portion). APS cameras do the same thing except that they record the panorama mode magnetically on the back of the film. The entire frame is exposed and you could later change your mind and ask the lab to print the whole frame.
You won't get very high image quality if you print from only a tiny portion of a tiny negative. But that doesn't mean you need a true panoramic camera. You could just use a big view camera and bring the resulting 4x5, 5x7, or 8x10 sheet of film into a pro lab and tell them to print only the central portion.
If that seems like a waste of film and effort, then the Fuji 617 that I own is for you. Fuji takes one of their 5x7 view camera lenses and attaches it to a body that handles 120 and 220 roll film. So the photographer is freed from the bulk of the 5x7 view camera, from the drudgery of loading sheet film into film holders, and from having to spend $6 per exposure on film and processing (instead it is perhaps $3 per exposure).
Panoramic cameras don't have the perspective correction flexibility of the view camera from which they were cut down. This is very annoying if you're trying to capture architecture in a city. Panoramic cameras don't have the close-focus capability of view cameras. This is annoying if you want to include a person's face prominently in your image. Panoramic cameras can be unbelievably expensive compared to the view cameras from which they are derived. For example, Linhof makes a 617 camera similar to my Fuji. A Schneider 72mm lens for the camera is $4000. The same lens ready for use on any view camera was $1500 (in December 1998).
There are panoramic cameras that do things you could never do with a view camera and cropping. These have rotating lenses that capture up to 360 degrees onto long strips of film, e.g., the $650 Spinshot camera makes 7 frames on a 36-exposure roll of 35mm film. The Noblex is the standard rotating-lens 120 roll-film camera. It captures 150 degrees on a 6x12 frame.
I'm not really an expert on panoramic photography but I think that the main advantage of the fixed lens camera is simplicity. A camera with a rotating lens can produce very strange results if the lens does not rotate smoothly. The big advantage for the rotating lens cameras, in addition to wide field of view, is that they are free of the edge distortion and light falloff that you get with wide angle lenses.
One thing to keep in mind is that if your panoramic camera produces an image that does not fit into a 4x5 enlarger, you won't be able to print images yourself in a darkroom and will be forced to used a professional laboratory where they have an 8x10 enlarger. Note that 6x12 fits in a 4x5 enlarger but 6x17 does not.
Friday, August 8, 2008
Life of the Trivals
They are young Marma women waiting in a shop at a Market day..........This is the way how they decorate them to make them selves attractive........... and another Marma family is taking bath as a part of their dailt routine..............................
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Making Photographs:06
a textbook by Philip Greenspun; revised January 2007
(after last publication)
Digital Backs for Medium-format and View Cameras
If you're not happy about paying Canon $2500 for a 24x36mm sensor wrapped in a fancy electronic body (Canon EOS 5D), perhaps you'd prefer to pay $30,000 for a 48x36mm sensor, camera not included. What do you get when you pay 10 times as much?
(after last publication)
Digital Backs for Medium-format and View Cameras
If you're not happy about paying Canon $2500 for a 24x36mm sensor wrapped in a fancy electronic body (Canon EOS 5D), perhaps you'd prefer to pay $30,000 for a 48x36mm sensor, camera not included. What do you get when you pay 10 times as much?
- a sensor that is double the size, offering superior low light performance
the requirement that you buy lenses designed for medium-format (120/220) film or this new digital format; these are much larger, heavier, and more expensive than lenses designed for small-sensor and film SLRs
an additional f-stop or two of dynamic range and 4 extra bits (16 extra levels) of information per color; the typical digital back puts out 16-bit RAWs- higher resolution, enabling printing up to about 2x the linear dimensions
the flexibility to attach the back to a variety of different camera systems, all of which are much more cumbersome to use than a Canon or Nikon body
To what kinds of cameras do these digital backs attach? View cameras and medium format SLRs.
A medium format SLR is easy to understand. It has all of the same components as the familiar Canon and Nikon SLRs, but everything has been scaled up. Hasselblad, Mamiya, and Rollei were the leading manufacturers of these cameras in the film days. They usually engineered the camera body and the film back in separate pieces. In the studio you'd attach the Polaroid back to check the lighting with a few test exposures ($3 each, kids!). Then you'd attach a back loaded with slide film for a few photos. If you wanted to be 100 percent sure that you had something usable, you'd attach a second back loaded with more forgiving color negative film for insurance. Standard frame sizes included 45x60mm, 60x60mm, and 60x70mm. When digital came along, it was only natural that people would engineer a back to fit the existing inventory of camera bodies and high quality lenses.
How well do these systems work? The most integrated is the Hasselblad H3D. The manufacturer claims "the ease of use of the best 35mm DSLRs", which means "not as fast or easy to use as a Canon or Nikon, but the fundamentals of viewing and photographing will probably work better."
What is the fundamental limitation with a medium-format SLR? The lens and the film are fixed parallel to each other. We can remove that, at the expense of ease of use, by attaching the digital back to a view camera.
View cameras are the most flexible cameras, usually made from a basic design that has not changed for over 100 years. A view camera is a light-tight bellows with a bracket at one end for a lens and a bracket at the other for the digital back. You compose and focus your image on a groundglass, then displace the glass with a sheet of film or a digital back. Adding to the challenge is the lack of a mirror or prism, which means that you view the image upside down and reversed left-to-right.
Why work this hard to take a photo? The flexibility of arbitrarily positioning lens and sensor opens up a huge range of creative opportunities that are unavailable to most photographers. For example, if you want to take a photo of a building, the obvious thing to do is point the camera up towards the center of the structure. However, this results in projecting the vertical exterior of the building onto the angled sensor surface. The lines of the building will converge towards the top of the frame. A view camera allows you to keep the camera level with the ground and either shift the lens up or the digital back down. The sensor is now "looking up" at the building through the lens, but the sensor is still parallel to the building exterior so lines don't converge.
If you're taking a picture of rocks in a stream with a view camera, you can achieve sharper focus by tilting the lens forward a bit. This will get the Scheimpflug Rule working for you: the planes of the subject, the lens, and the sensor should all intersect in a line. You can achieve the same result by leaving the lens fixed and tilting the sensor back a bit. This will improve the focus and also increase the relative prominence of nearby rocks since they will be stretched out onto the film.
A complete view camera system consists of the camera, a couple of lenses, the digital back, a dark cloth, a focusing loupe, a tripod, etc. Complete with protective case, it will weigh at least 30 lbs. and you will agree with the wise 8x10" photographer who said "If it is more than 100 yards from the car, it's not photogenic."
Companies that make digital backs include Hasselblad, Leaf, MegaVision, Phase One, and Sinar.
Panoramic Cameras
If you want the maximum in convenience and image quality, there are purpose-built wide-angle and 360-degree panoramic cameras that incorporate a line of CCD sensors and a motor to scan the sensors behind the lens. The folks at Roundshot will be happy to sell you one for about $30,000. Keep in mind that, with a scanning back, different portions of the image will be captured as much as a few seconds apart. Files range in size up to 470 megapixels.
Film Cameras
We've arrived at the last and, to my mind, least important chapter in the text. As noted on the cover page, this is where most photography textbooks start. Generally your choice of camera will not have much effect on the final image. Certainly the brand of camera that you choose will have virtually no effect. However, if you're a nerd like me, there is a certain satisfaction in knowing what tools are available to the photographer and how they work. Here are the factors that go into the choice of a camera for a project:
What is the required final image quality?
At what magnification will the image be viewed?
How much weight can you carry to the subject?
How much time do you have to take the picture?
Suppose that your project demands high image quality and high magnification. For example, you are going to make a 20 x 24 inch enlargement and display it in a corridor where people can walk right up to it to check out fine detail. This requirement pushes you toward using a large piece of film for the original exposure. The large piece of film will require a large relatively heavy camera surrounding it, which gets us into Factor 3: "How much weight can you carry to the subject?"
Annie Leibowitz goes to a portrait session with several assistants carrying her heavy Mamiya camera that exposes a 6 x 7 cm negative (4.5 times the area of a 35mm negative). Ansel Adams would pack his 8 x 10 inch camera into the Sierra with a mule. If you're the mule and your subject isn't in your home or photo studio, think about whether you'll have the energy to take any pictures after carrying around a particular camera and its accessories.
Different cameras work at different speeds. With the latest Canon or Nikon autofocus systems, you might be able to capture an unanticipated event on a soccer field. Ansel Adams could not have done this with an 8 x 10 view camera, which requires many minutes for setting up the tripod, focusing, stopping the lens down to taking aperture, closing the shutter, cocking the shutter, film loading, dark slide removal, and exposure. If your subject is a big mountain, you can probably afford to take your time making the image.
Now that we have the factors in mind, let's dive into the types of cameras available:
view cameras (sheet film + perspective control)
single-lens reflex cameras (roll film, heavy in larger formats, very limited perspective control)
twin-lens reflex cameras (roll film, light and cheap, no perspective control)- rangefinder cameras (roll film, lightweight, no perspective control)
panoramic cameras (view camera lens + rangefinder body or rotating lens)
Film Sizes
A camera won't do you much good unless you can buy film in the right size for it. Companies like Fuji and Kodak will generally make the same emulsion (film formulation) in a variety of sizes.
Almost every emulsion will be available in 35mm cartridges. The standard frame size for a 35mm camera is 24 x 36 mm.
Most emulsions are available in "120 size" roll film. There are many standard widths for 120 camera frames: 645, 6x6, 6x7, 6x8, 6x9, 6x12, and 6x17. These numbers are ostensibly in centimeters although in practice a 6x6 camera such as a Hasselblad will expose a 56 x 56 mm frame. Comparatively few emulsions are available in 220, which is the same as 120 except that you get twice as many exposures/roll (24 rather than 12 for 6x6; 8 rather than 4 for 6x17 panoramics).
If you need a larger negative than roll film, you must use sheet film. Standard American sizes are 4x5, 5x7, 8x10, and 11x14. The dimensions are in inches. The largest sizes are wonderful for those who do darkroom work because they can be contact-printed into final framable results, avoiding the degradation of an enlarger lens. However, there is very little emulsion choice in 11x14 and not too much in 8x10 or 5x7 either. Given the high quality of modern optics and film, for most applications these days, a 4 x 5 inch sheet of film is large enough. Therefore that's where most of the demand is and where you get the best choice of emulsions.
I'm not going to let my article on APS film and cameras serve as my repository for what I know about this format (somewhat smaller than 35mm). Despite the intriguing nature of spy cameras such as the Minox (Austin Powers used one to copy documents), film formats significantly smaller than 35mm are generally not useful for serious photographers.
View Cameras
View cameras are the most flexible cameras, usually made from a basic design that has not changed for over 100 years. You know the guy in the old time photo studio who photographs with his head under a cloth? He's using a view camera. Edward Weston? He took most of his best photos with an 8x10" view camera. All those luscious ads for food in magazines? Taken with view cameras.
A view camera is fundamentally a light-tight box with a slot at one end for a lens and a slot at the other for the film. You compose and focus your image on a groundglass, then displace the glass with a sheet of film in a film holder.
The lens and film aren't fixed parallel to each other. This opens up a huge range of creative opportunities that are unavailable to most photographers. For example, if you want to take a photo of a building, the obvious thing to do is point the camera up towards the center of the structure. However, this results in projecting the vertical exterior of the building onto the angled film surface. The lines of the building will converge towards the top of the frame. A view camera allows you to keep the camera level with the ground and either shift the lens up or the film down. The film is now "looking up" at the building through the lens, but the film is still parallel to the building exterior so lines don't converge.
If you're taking a picture of rocks in a stream with a view camera, you can achieve sharper focus by tilting the lens forward a bit. This will get the Scheimpflug Rule working for you: the planes of the subject, the lens, and the film should all intersect in a line. You can achieve the same result by leaving the lens fixed and tilting the film standard back a bit. This will improve the focus and also increase the relative prominence of nearby rocks since they will be stretched out onto the film.
If you want to understand view cameras, you can start by reading B&H Photo's introduction to large format and the standard textbook on the topic: View Camera Technique. I provide some view camera sample images in my FlashPix References Images collection.
Single lens reflex (SLR)
Suppose that the photographer has chosen an exposure of f/8 and 1/125th of a second. Here is how most SLRs work during exposure:
- lens is kept open to maximum aperture (e.g., f/2.8) for ease of viewing and metering
when the user presses the shutter release, the lens aperture is stopped down to the taking aperture of f/8. On old-style camera/lens interfaces (e.g., Nikon, Hasselblad), this is accomplished by moving a lever. With camera/lens interfaces designed in the 1980s (e.g., Canon, Rollei), this is accomplished by sending an electrical signal to a solenoid in the lens.
the mirror is flipped up out of the way of the light (and parked flat up against the prism)
now that the lens is stopped down and the mirror is up, the shutter opens and light begins to strike the film
as soon as the shutter is fully open, the camera signals an electronic flash, if attached to fire- when 1/125th of a second has elapsed, the shutter is closed
the mirror is pushed back down to viewing position
the lens aperture is reopened to its widest setting
SLR manufacturers generally provide a range of interchangeable lenses. This works out nicely because changing the lens simultaneously changes the scene magnification on film and in the viewfinder. Unlike view cameras, it is tough to mix and match brands. Camera bodies and lenses are coupled mechanically and perhaps electronically in non-standard ways (partly to accomplish the exposure sequence detailed above). So a lens for a Hasselblad SLR won't fit a Rollei and a Canon EOS lens won't fit a Nikon body.
The best thing about an SLR is that what-you-see-is-what-you-get. If you've left the lens cap on, fitted a really long telephoto, attached a strange filter, you can see the effect in the viewfinder. This is also true for a view camera, but with an SLR the image is right-side up and available until a few milliseconds before the exposure.
One obvious problem with an SLR is weight. The prism on top of the body that lets you see a properly-oriented image is heavy. For medium-format SLRs, the prism is very heavy and is usually optional. If you don't mind looking down into the camera and seeing an image that is reversed left-to-right, you can use a lightweight metal viewing hood rather than a prism.
Another problem with the SLR is noise. The mirror is light but it has to be flipped up as fast as possible. This is noisy. With a medium-format SLR, the mirror is four times the size of a Nikon's and very noisy.
A final problem with an SLR is exposure latency. If you wait for the decisive moment and press the shutter, the camera doesn't take a picture until it has stopped down the lens and flipped up the mirror. This takes between 50 and 100 milliseconds for the average 35mm SLR.
Note that a few 35mm SLRs have been built with fixed semi-transparent mirrors called "pellicle mirrors". The Canon EOS line includes a cheap discontinued EOS RT model and an expensive current EOS-1 RS model. The RS's mirror sends one-third of the light to the viewfinder and two-thirds to the film. Thus the viewfinder is more than 1 f-stop dimmer than a standard camera and the film gets 2/3 f-stop less light than with a standard camera. Advantages are that the picture gets taken 6 ms after you press the shutter release, you retain your view of the subject at the exact moment of exposure, the motor drive can operate at a blistering 10 frames per second, and there is less vibration.
Twin lens reflex (TLR)
A twin-lens reflex has two lenses (the twin lens) and a mirror to bounce the light from one of them onto a ground-glass focusing screen (the reflex). Lacking a prism, a TLR tends to be lightweight. Since the mirror remains fixed at all times, a TLR tends to be quiet and exposure lag is minimal. TLRs are mechanically very simple. Consider that in an SLR the lens must have an automatic diaphragm that remains open until the instant before exposure, then stops down quickly to taking aperture. With a TLR, there are separate taking and viewing lenses and therefore the aperture knob can directly open and close the diaphragm blades.
TLRs suffer from potential misalignment, e.g., when the image is focussed on the ground glass by the viewing lens, it might not be focussed on the film plane by the taking lens.
TLRs suffer from parallax. The viewing lens is higher than the taking lens and captures a different image. If the image is a mountain 20 miles away, the three inches of separation won't be significant. However, you can forget about doing macro work and you might get interesting framing errors if you're close to the subject.
The classic collectible TLR is the Rolleiflex, which takes 120 and 220 roll film. Though there is no technical reason why TLRs couldn't be built for other film sizes, virtually all make 6x6 cm images on 120 film. The TLR that poor photography students use is the Yashica 124 (see photo at right; I took it during my junior year at MIT). The TLR that wedding photographers use is the Mamiya because you can change the lenses. The only TLRs currently in production are the Rolleiflex, which is priced from $3000 and sold to collectors, and various Chinese-made inexpensive toys (e.g., the Seagull for about $130). Used Mamiyas, Rolleiflexes, and Yashicas are common, however, and quite inexpensive. They are great for people taking darkroom classes who don't have much money but want a larger easier-to-handle negative.
Rangefinder and lens-shutter cameras
The simplest lens-shutter cameras are like my Fuji 617. Fuji took a view camera lens, with its shutter, and glued it to a rigid body that holds roll film. You lose the perspective control of a view camera but the result is a much simpler and more compact camera. Focusing on the simplest lens-shutter cameras is done by "guestimation"; the focusing ring on the lens is marked in feet and meters. You try to figure out how far away your subject is and then turn the ring accordingly.
Most SLRs have focal-plane shutters. After all, if you're going to buy 10 lenses and one body, it makes more sense to put an expensive shutter only in the body. But if you've got a camera with a permanently affixed lens, it makes just as much sense to put the shutter in the lens. In fact, if a lens is very small, as with a consumer's point and shoot camera, a between-the-lens shutter can often be very small and therefore cheaper and faster than a focal-plane shutter that must cover the entire exposed film area.
With a lens-shutter or rangefinder camera, you can't look through the lens. You view the image through a separate optical viewfinder. As with the TLR, the image on film will be a bit different than what you viewed due to parallax: the viewfinder isn't exactly aligned with the lens.
It turns out that people aren't very good at estimating distance precisely. So companies began putting military rangefinders into lens-shutter cameras, coupled to the lens and the viewfinder. The photographer turns a ring on the lens until two superimposed images are aligned in the viewfinder.
Modern lens-shutter cameras tend to have some sort of autofocus mechanism.
Without the mirror and prism, lens-shutter cameras can be much lighter and more compact than an SLR using the same film format. Mamiya and Fuji roll-film rangefinders are actually lighter than the big Nikon and Canon 35mm SLRs, despite the fact that roll-film cameras produce a negative that is four times the size.
With no mirror to slap, lens-shutter cameras are also much quieter than SLRs. The United Nations, for example, requires that photographers use Leica 35mm rangefinder cameras to record events.
History of painting: 06
(after last publication)
International Gothic: 14th - 15th century AD
The Europe of the Middle Ages, dominated by a powerful church and criss-crossed by pilgrim routes, has enjoyed a culture which largely transcends geographical regions. It is appropriate therefore that the final style of medieval art should also be common to much of the continent.
This style, flourishing between about 1375 and 1425, is known to art historians as International Gothic - or sometimes simply the International Style. It is characterized by figures of a slender and even winsome elegance, painted with great confidence but looking somewhat ill-equipped for the hurly-burly of everyday life. The style can be traced back to Italian artists of the early 14th century, such as Simone Martini.
It reaches its mature form at the end of the century. The Wilton Diptych, painted in about 1395-9 and now in London's National Gallery, is often quoted as an outstanding example. Against gilded backgrounds a kneeling king, Richard II, is presented by three saints to the Virgin and Child and a host of blue-robed angels.
The stillness of the scene, and the beauty of the robes and the angels' wings, makes this a glimpse of an ideal world. Its international quality is attested by the inability of the experts to decide whether it was painted in England, France, Italy or Bohemia. This international style features in a more relaxed and secular form (though still with the same slender decorative figures) in the prayer books or 'books of hours' illustrated in the early 15th century for the duke of Berry, a member of the French royal family. The most famous of them is the Très Riches Heures (Very Rich Hours), illustrated between about 1411 and 1416 by the three Limburg brothers.
The artists, from the border region between modern Germany and Belgium, provide beautiful images of the duke's many castles and of his peasants working in the fields, as well as scenes from the gospel story. In their confident control of space within each picture, and in the natural ease of their human figures, the Limburg brothers have something in common with other artists of their generation who are the founding figures of the Renaissance.
But a certain decorative quality, a prettiness, a lack of emotional conviction, makes the painters of International Gothic a transitional group between medieval and Renaissance. In the decades after the Très Riches Heures, in Flanders to the north and in Italy to the south, images of a new kind are created. These Flemish and Italian artists are very different from each other, but they share a solidity and a solemnity lacking in International Gothic.
to be continued………………
International Gothic: 14th - 15th century AD
The Europe of the Middle Ages, dominated by a powerful church and criss-crossed by pilgrim routes, has enjoyed a culture which largely transcends geographical regions. It is appropriate therefore that the final style of medieval art should also be common to much of the continent.
This style, flourishing between about 1375 and 1425, is known to art historians as International Gothic - or sometimes simply the International Style. It is characterized by figures of a slender and even winsome elegance, painted with great confidence but looking somewhat ill-equipped for the hurly-burly of everyday life. The style can be traced back to Italian artists of the early 14th century, such as Simone Martini.
It reaches its mature form at the end of the century. The Wilton Diptych, painted in about 1395-9 and now in London's National Gallery, is often quoted as an outstanding example. Against gilded backgrounds a kneeling king, Richard II, is presented by three saints to the Virgin and Child and a host of blue-robed angels.
The stillness of the scene, and the beauty of the robes and the angels' wings, makes this a glimpse of an ideal world. Its international quality is attested by the inability of the experts to decide whether it was painted in England, France, Italy or Bohemia. This international style features in a more relaxed and secular form (though still with the same slender decorative figures) in the prayer books or 'books of hours' illustrated in the early 15th century for the duke of Berry, a member of the French royal family. The most famous of them is the Très Riches Heures (Very Rich Hours), illustrated between about 1411 and 1416 by the three Limburg brothers.
The artists, from the border region between modern Germany and Belgium, provide beautiful images of the duke's many castles and of his peasants working in the fields, as well as scenes from the gospel story. In their confident control of space within each picture, and in the natural ease of their human figures, the Limburg brothers have something in common with other artists of their generation who are the founding figures of the Renaissance.
But a certain decorative quality, a prettiness, a lack of emotional conviction, makes the painters of International Gothic a transitional group between medieval and Renaissance. In the decades after the Très Riches Heures, in Flanders to the north and in Italy to the south, images of a new kind are created. These Flemish and Italian artists are very different from each other, but they share a solidity and a solemnity lacking in International Gothic.
to be continued………………
The History of Motion Pictures:07
(after last publication)
Narrative film construction
The way forward to making films made up of more than one shot was led by films of the life of Jesus Christ. The first of these was made in France in 1897, and it was followed in the same year by a film of the Passion play staged yearly in the Czech town of Horitz. This was filmed by Americans for exhibition outside the German-speaking world, and was presented in special venues, not as a continuous film, but with the separate scenes interspersed with lantern slides, a lecture, and live choral numbers, to increase the running time of the spectacle to about 90 minutes.
Films of acted reproductions of scenes from the Greco-Turkish war were made by Georges Méliès in 1897, and although sold separately, these were no doubt shown in continuous sequence by exhibitors. In 1898 a few films of similar kind were made, but still none had continuous action moving from one shot into the next. The multi-shot films that Georges Méliès made in 1899 were much longer than those made by anybody else, but l’Affaire Dreyfus (The Dreyfus Case) and Cendrillon (Cinderella) still contained no action moving from one shot to the next one. Also, from Cendrillon onwards, Méliès made a dissolve between every shot in his films, which reduced any appearance of action continuity even further. To understand what is going on in both these films, the audience had to know their stories beforehand, or be told them by a presenter.
to be continued………………
Narrative film construction
The way forward to making films made up of more than one shot was led by films of the life of Jesus Christ. The first of these was made in France in 1897, and it was followed in the same year by a film of the Passion play staged yearly in the Czech town of Horitz. This was filmed by Americans for exhibition outside the German-speaking world, and was presented in special venues, not as a continuous film, but with the separate scenes interspersed with lantern slides, a lecture, and live choral numbers, to increase the running time of the spectacle to about 90 minutes.
Films of acted reproductions of scenes from the Greco-Turkish war were made by Georges Méliès in 1897, and although sold separately, these were no doubt shown in continuous sequence by exhibitors. In 1898 a few films of similar kind were made, but still none had continuous action moving from one shot into the next. The multi-shot films that Georges Méliès made in 1899 were much longer than those made by anybody else, but l’Affaire Dreyfus (The Dreyfus Case) and Cendrillon (Cinderella) still contained no action moving from one shot to the next one. Also, from Cendrillon onwards, Méliès made a dissolve between every shot in his films, which reduced any appearance of action continuity even further. To understand what is going on in both these films, the audience had to know their stories beforehand, or be told them by a presenter.
to be continued………………
Thursday, August 7, 2008
Making Photographs:05
a textbook by Philip Greenspun; revised January 2007
(after last publication)
What about megapixels?
Photo quality in a final print is 200 pixels per inch (the "300dpi" figure that you hear sometimes relates to commercial printing presses and isn't meaningful for digital cameras and digital lab printers). That said, 200 pixels per inch is no guarantee of high quality. The 10-megapixel point and shoot camera may have low contrast and sharpness from the cheap lens plus high noise in shadow areas from the small sensor. You would probably get a better print from an old 6-megapixel digital SLR.
(after last publication)
What about megapixels?
Photo quality in a final print is 200 pixels per inch (the "300dpi" figure that you hear sometimes relates to commercial printing presses and isn't meaningful for digital cameras and digital lab printers). That said, 200 pixels per inch is no guarantee of high quality. The 10-megapixel point and shoot camera may have low contrast and sharpness from the cheap lens plus high noise in shadow areas from the small sensor. You would probably get a better print from an old 6-megapixel digital SLR.
2000x3000 pixels (6 megapixels); good for prints up to 10x15" in size
2700x3600 pixels (10 megapixels, average digital SLR); good for prints up to 13x18" in size
2900x4400 pixels (13 megapixels, Canon 5D); good for prints up to 15x22" in size
3300x5000 pixels (16.6 megapixels, Canon 1 Ds Mark II); prints up to 17x25"
4080x5440 pixels (22 megapixels; medium format backs); prints to 20x27"
5400x7200 pixels (39 megapixels; medium format backs); prints to 27x36"
10000x14000 pixels (140 megapixels; large format scanning backs); prints to 50x70"
Note that the "print size" is the maximum at which you'll get the kind of print quality that one would have gotten with the best film equipment, enlarged no more than about 10x. By this standard, the largest that you could have enlarged the typical 35mm negative before a noticeable reduction in quality would be 10x15", the same as the 6-megapixel digital SLRs. A 6x7cm medium format negative at 10x will enlarge to 24x28". A 4x5" sheet of film could enlarge to 40x50" and withstand close inspection.
What about dynamic range?
A glossy photographic print has a dynamic range of about 100:1, i.e., the brightest highlight reflects about 100 times more light than the darkest shadow. This is a 6.6 f-stop range, 2 raised to the 6.6 power being close to 100. Ultimately our goal is to represent a real-world scene within this 100:1 ratio. How tough should that be? Things in the real world are either white like the blank photographic paper, black like a shadow printed on the photographic paper, or somewhere in between. You'd therefore naively imagine that a typical real-world scene would have about the same dynamic range as a photographic print.
Materials in the real world, however, are more varied than the photographic paper. Snow is extremely reflective while black velvet or matte black paint have textures that absorb light. Differences in surface properties can push the dynamic range of a real-world scene up over 200:1, which is all the dynamic range you'd need if not for shadows. Consider a granite cliff face with bright white highlights. Add a cave. The interior of the cave will be dark, despite the fact that it is made of the same rock as the cliff. The fact that the cave interior is in shadow and receiving a very different amount of light than the rocks and trees outside adds a huge amount of contrast. Now put a black bear inside that cave and try to take a photo that captures detail in the shadowed-by-the-cave bear's face and the lit-by-the-sun cliff face. You're struggling with as much as 16 f-stops of dynamic range or 64,000:1. For practical purposes, a high-contrast real-world scene is usually limited to 1000:1, or 10 f-stops.
Thus the digital photographer is presented with two challenges: (1) capturing the full range of tones that are present in a scene, (2) figuring out how to map those tones into the more limited range that is representable in a finished print.
How many bits are necessary to capture our 1000:1 scene? As 2 raised to the 10th power is 1024, one would naively suppose 10 bits, but, since the RAW files are encoded linearly, that would leave only two levels in the dark shadows: on and off. The result would be banding in the shadows. We will have to add a couple of extra bits to ensure the same number of levels that the human eye can distinguish. We therefore need at least 12 bits per color, which is coincidentally what the mid-range digital camera RAW formats provide. That will be sufficient to capture a high-contrast scene, assuming the exposure setting is perfect. The expensive digital camera backs, some of which incorporate electronic cooling to reduce sensor noise in the shadows, offer a 12 f-stop dynamic range and output 16 bits.
What if you capture JPEG files, in effect asking the camera to do the RAW to JPEG conversion? A standard JPEG encodes 8 bits per color or 256 levels and incorporates a gamma factor so that the numbers do not linearly correspond to luminance. The human eye can distinguish roughly 200 levels with the 6.6 f-stop range of a final print. Therefore a perfectly exposed and converted JPEG ought to be adequate for making the best possible final print. Unfortunately, in practice, the exposure won't be perfect and the computer in the camera won't make the same same decision that you or a professional darkroom technician would about how highlights and shadows ought to be mapped into the print tones.
Unless you're going to do all of your photography in a studio with controlled lighting and a calibrated camera-to-printer setup, you must have a camera that outputs RAW files with at least 12 bits per color. This rules out nearly every point and shoot-style camera.
Point and Shoot
Well, they're compact, but due to the small sensor and small lens, you can almost always get substantially higher image quality if you're willing to carry a larger camera. The megapixel count will undoubtably be high, but the contrast and sharpness will be low and the shadow noise high. Very few P&S cameras provide a RAW capture option, so the number of luminance levels is limited to 256, only 1/16th as many as you'd get with a 12-bit RAW from a low-end digital SLR. We cover point and shoot cameras in a separate article.
Single lens reflex (SLR)
A single lens reflex (SLR) is a camera in which the same lens is used for viewing and taking pictures. A mirror in the body directs the light from the lens up into a prism for viewing, then flips up out of the way just before an exposure is made. Note that this is not an exotic technology; the standard Nikon or Canon camera body (photo at right) is an SLR. Suppose that the photographer has chosen an exposure of f/8 and 1/125th of a second. Here is how most SLRs work during exposure:
lens is kept open to maximum aperture (e.g., f/2.8) for ease of viewing and metering
when the photographer presses the shutter release, the lens aperture is stopped down to the taking aperture of f/8. On old-style camera/lens interfaces (e.g., Nikon, Hasselblad), this is accomplished by moving a lever. With camera/lens interfaces designed in the 1980s (e.g., Canon, Rollei), this is accomplished by sending an electrical signal to a solenoid in the lens.
the mirror is flipped up out of the way of the light (and parked flat up against the prism)
now that the lens is stopped down and the mirror is up, the shutter opens and light begins to strike the CCD or CMOS sensor- as soon as the shutter is fully open, the camera signals an electronic flash, if attached to fire
- when 1/125th of a second has elapsed, the shutter is closed
- the mirror is pushed back down to viewing position
- the lens aperture is reopened to its widest setting
SLR manufacturers generally provide a range of interchangeable lenses. This works out nicely because changing the lens simultaneously changes the scene magnification on film and in the viewfinder. It is tough to mix and match brands. Camera bodies and lenses are coupled mechanically and electronically in non-standard ways. A lens for a Canon EOS body won't fit a Nikon body and vice versa.
The best thing about an SLR is that what-you-see-is-what-you-get. If you've left the lens cap on, fitted a really long telephoto, attached a strange filter, you can see the effect in the viewfinder.
One obvious problem with an SLR is weight. The prism on top of the body that lets you see a properly-oriented image is heavy.
Another problem with the SLR is noise. The mirror is light but it has to be flipped up as fast as possible, which is necessarily noisy. Photographers who work during live theater or concerts often surround the camera in a "blimp" to muffle the noise.
A final problem with an SLR is exposure latency. If you wait for the decisive moment and press the shutter, the camera doesn't take a picture until it has stopped down the lens and flipped up the mirror. This takes between 50 and 100 milliseconds for the average SLR, which can be reduced to about 40 milliseconds by using the mirror lock-up custom function. A standard digital camera uses the final 40 milliseconds to register dark current levels from the image sensor. These levels vary based on temperature and other conditions, and must therefore be updated for every picture or sequence of exposures.
[Do not confuse an electronic viewfinder (EVF) point and shoot camera with a true mirror-and-optics SLR. The EVF camera is sending light continuously to the sensor and feeding the sensor output to a little TV screen on top of the camera. Physically the format is very similar to a true SLR, but current TV screen technology isn't nearly as good as current optics.] More on this kind of camera: "Building a Digital SLR System".
Rangefinder and lens-shutter cameras
The simplest camera would include the following components:
a lens in front, with diaphragm for aperture control
a focus ring or bellows to move the lens back and forth
a shutter in the middle of the lens
a light-sensitive medium, film or digital sensor, at the back
Such cameras have been common since the invention of photography and are known as lens-shutter cameras.
With a lens-shutter or rangefinder camera, you can't look through the lens. You view the image through a separate optical viewfinder. The image that you take home will be a bit different than what you viewed due to parallax: the viewfinder isn't exactly aligned with the lens.
It turns out that people aren't very good at estimating distance precisely. So companies began putting military rangefinders into lens-shutter cameras, coupled to the lens and the viewfinder. The photographer turns a ring on the lens until two superimposed images are aligned in the viewfinder. The only digital cameras that include traditional optical/manual rangefinders are the Epson R-D1 and the Leica M8. Both accept lenses from the Leica M film camera system, which are designed for the 24x36mm frame of 35mm film. Both the Epson and Leica digital rangefinders incorporate a small sensor, thus multiplying the effective focal length of the old lenses. These cameras accept a large range of lenses and therefore use a shutter just in front of the sensor, i.e., a focal-plane shutter.
If you put an autofocus and autoexposure mechanism into a traditional lens-shutter camera, what do you have? A consumer's point and shoot camera.
Without the mirror and prism, lens-shutter cameras can be much lighter and more compact than an SLR using the same sensor. With no mirror to slap, lens-shutter cameras are also quieter than SLRs.
There is no mass market for high quality digital rangefinder cameras and therefore the cameras that are available are much more expensive that SLRs that produce the same image quality. The image quality of the best SLRs is not available at any price from a digital rangefinder.
to be continued………………
History of painting:05
(after last publication)
The Scrovegni Chapel: AD 1300-1310
In 1300 Enrico degli Scrovegni, son of a rich banker, buys the derelict site of an old Roman arena in Padua. On it he builds a house for himself and a chapel. Variously known now as the Scrovegni Chapel or Arena Chapel (from its site), this little building is the first great milestone in Italian art and an early pointer in the direction of the Renaissance.
The reason is that the frescoes on its walls are the chief masterpiece of Giotto. The artist is already working in a Franciscan church in Padua, probably in about 1305, when Scrovegni employs him for his arena project. Giotto undoubtedly uses assistants, for the sequence of frescoes - covering every inch of the interior walls - is completed in about two years. But the detailed schematic arrangement is entirely his, together with the greater part of the painting.
The brilliance of the scheme is that the entire gospel story of the Holy Family, spanning three generations (the Virgin's parents, the Virgin herself and Jesus) is told with great clarity and drama in the panels which run, like a strip cartoon, in three rows along the walls.
The Annunciation has the central position at the top of the east wall, but this is also its correct place in the narrative sequence.
The genius of Giotto
The elegance of the chapel's overall scheme would be nothing without the power of the paintings themselves. Giotto's genius is revealed both in his way of dramatising each moment and in his treatment of the figures. Each panel is like a small stage on which the artist arranges the players to reveal the drama, just as a director would in the theatre. But these are painted people, unable to move. In the earlier Byzantine tradition a virtue is made of this limitation. Byzantine figures are richly static, as if selecting and holding a significant expression or gesture. Giotto loses none of the solemnity of Byzantine art, but he adds solidity.
Giotto achieves a three-dimensional quality, a sense of depth and space, by his unprecedented use of modelling, shadow and perspective. These skills in themselves makes his people appear more real, but Giotto's sturdy approach to the human face and body adds another new element. His people are more than real. They have a heroic stillness, a superhuman quality which becomes a characteristic of Italian Renaissance art - seen over the next 250 years in artists such as Masaccio, Piero della Francesca and Michelangelo.
The final magical ingredient of these frescoes is an implied sense of movement. Artists have often found ways of depicting limbs in action, as far back as the bullfighting acrobat in Minoan Crete. But Giotto's secret is different.
His hint of movement is that of a coiled watch spring. He freezes his figures just when the energy is already in place for the next moment. Numerous good examples could be found in the Scrovegni Chapel. My own favourite, perhaps, would be the mother of the Virgin gently pushing the young girl up the steps for her presentation in the temple. In addition to the originality of Giotto's work, the chapel points to the future in another way. Scrovegni himself is painted by Giotto, at the base of the Last Judgement on the west wall, presenting his chapel to three female saints. Rich private donors, keeping company with saints, will become a feature of Renaissance art.
Scrovegni is one of the first. He has good reason to wish to be seen in holy company, for his wealth derives from his father's sin of usury. The chapel is an expiation for that sin. Scrovegni would surely be astonished to know how much credit has accrued to his family name over the centuries, thanks to his father's tainted money and his own immaculate taste.
Duccio and the Maestà in Siena: AD 1308-1311
In the same decade as Giotto's chapel in Padua, another masterpiece of Christian narrative is created in Siena. In 1308 the cathedral authorities commission from Duccio the great altarpiece now known as the Maestà ('Majesty').
The tradition of the altarpiece, with panels depicting holy figures, goes back many centuries to the lavish blend of gold and jewels and enamelled scenes favoured by Byzantine emperors for the altars of their churches.
In those cases the scenes depicted are simple. But Duccio, like Giotto in Padua, undertakes something much more ambitious - an account, in narrative scenes, of the whole Christian story. Duccio has only two sides of a great screen to decorate (the development of the ambulatory behind the altar means that pilgrims can marvel at both back and front), whereas Giotto has all the walls of a chapel. But the Sienese painter boldly undertakes even more scenes than his rival.
There are about 40 narrative panels in Padua and nearly 60 in Siena, reinforcing the great central scene of the Virgin and Child enthroned. Duccio and his assistants work as fast as the team in Padua in their creation of this marvellous object. The documents reveal that on 9 June 1311 it is carried in a joyous musical procession from Duccio's studio to the cathedral - where it remains on show nowadays in a specially built museum. Duccio's treatment of the people in the gospel story shares the new realism of Giotto, though the overall style of these panels with their gilded backgrounds has elements of the Byzantine tradition of Christian art.
With these masterpieces in Padua and Siena, Italian painters bring to a new peak two great traditions of Christian art - the fresco cycle and the altarpiece. The panels in later frescoes become larger, eventually filling the whole wall (as, for example, in Raphael's Stanze in Rome). In altarpieces, by contrast, the narrative subsequently shrinks to a few incidents in the predella, allowing maximum emphasis on the central scene of the Virgin and Child or of the Crucifixion. Duccio's work contains elements of two styles which will later go their separate ways, each bringing results of great beauty. The chunky realistic quality which he shares (to a lesser degree) with Giotto reappears a century later in the work of Masaccio, leading to a strong native Italian tradition. Meanwhile a more refined and slender quality in some of Duccio's figures is developed by Simone Martini, the greatest Sienese painter of the next generation and possibly trained in Duccio's studio. Simone's Annunciation in the Uffizi is a good example of this refined style, which by the end of the 14th century is popular throughout Europe - becoming known later as International Gothic.
to be continued………………
The Scrovegni Chapel: AD 1300-1310
In 1300 Enrico degli Scrovegni, son of a rich banker, buys the derelict site of an old Roman arena in Padua. On it he builds a house for himself and a chapel. Variously known now as the Scrovegni Chapel or Arena Chapel (from its site), this little building is the first great milestone in Italian art and an early pointer in the direction of the Renaissance.
The reason is that the frescoes on its walls are the chief masterpiece of Giotto. The artist is already working in a Franciscan church in Padua, probably in about 1305, when Scrovegni employs him for his arena project. Giotto undoubtedly uses assistants, for the sequence of frescoes - covering every inch of the interior walls - is completed in about two years. But the detailed schematic arrangement is entirely his, together with the greater part of the painting.
The brilliance of the scheme is that the entire gospel story of the Holy Family, spanning three generations (the Virgin's parents, the Virgin herself and Jesus) is told with great clarity and drama in the panels which run, like a strip cartoon, in three rows along the walls.
The Annunciation has the central position at the top of the east wall, but this is also its correct place in the narrative sequence.
The genius of Giotto
The elegance of the chapel's overall scheme would be nothing without the power of the paintings themselves. Giotto's genius is revealed both in his way of dramatising each moment and in his treatment of the figures. Each panel is like a small stage on which the artist arranges the players to reveal the drama, just as a director would in the theatre. But these are painted people, unable to move. In the earlier Byzantine tradition a virtue is made of this limitation. Byzantine figures are richly static, as if selecting and holding a significant expression or gesture. Giotto loses none of the solemnity of Byzantine art, but he adds solidity.
Giotto achieves a three-dimensional quality, a sense of depth and space, by his unprecedented use of modelling, shadow and perspective. These skills in themselves makes his people appear more real, but Giotto's sturdy approach to the human face and body adds another new element. His people are more than real. They have a heroic stillness, a superhuman quality which becomes a characteristic of Italian Renaissance art - seen over the next 250 years in artists such as Masaccio, Piero della Francesca and Michelangelo.
The final magical ingredient of these frescoes is an implied sense of movement. Artists have often found ways of depicting limbs in action, as far back as the bullfighting acrobat in Minoan Crete. But Giotto's secret is different.
His hint of movement is that of a coiled watch spring. He freezes his figures just when the energy is already in place for the next moment. Numerous good examples could be found in the Scrovegni Chapel. My own favourite, perhaps, would be the mother of the Virgin gently pushing the young girl up the steps for her presentation in the temple. In addition to the originality of Giotto's work, the chapel points to the future in another way. Scrovegni himself is painted by Giotto, at the base of the Last Judgement on the west wall, presenting his chapel to three female saints. Rich private donors, keeping company with saints, will become a feature of Renaissance art.
Scrovegni is one of the first. He has good reason to wish to be seen in holy company, for his wealth derives from his father's sin of usury. The chapel is an expiation for that sin. Scrovegni would surely be astonished to know how much credit has accrued to his family name over the centuries, thanks to his father's tainted money and his own immaculate taste.
Duccio and the Maestà in Siena: AD 1308-1311
In the same decade as Giotto's chapel in Padua, another masterpiece of Christian narrative is created in Siena. In 1308 the cathedral authorities commission from Duccio the great altarpiece now known as the Maestà ('Majesty').
The tradition of the altarpiece, with panels depicting holy figures, goes back many centuries to the lavish blend of gold and jewels and enamelled scenes favoured by Byzantine emperors for the altars of their churches.
In those cases the scenes depicted are simple. But Duccio, like Giotto in Padua, undertakes something much more ambitious - an account, in narrative scenes, of the whole Christian story. Duccio has only two sides of a great screen to decorate (the development of the ambulatory behind the altar means that pilgrims can marvel at both back and front), whereas Giotto has all the walls of a chapel. But the Sienese painter boldly undertakes even more scenes than his rival.
There are about 40 narrative panels in Padua and nearly 60 in Siena, reinforcing the great central scene of the Virgin and Child enthroned. Duccio and his assistants work as fast as the team in Padua in their creation of this marvellous object. The documents reveal that on 9 June 1311 it is carried in a joyous musical procession from Duccio's studio to the cathedral - where it remains on show nowadays in a specially built museum. Duccio's treatment of the people in the gospel story shares the new realism of Giotto, though the overall style of these panels with their gilded backgrounds has elements of the Byzantine tradition of Christian art.
With these masterpieces in Padua and Siena, Italian painters bring to a new peak two great traditions of Christian art - the fresco cycle and the altarpiece. The panels in later frescoes become larger, eventually filling the whole wall (as, for example, in Raphael's Stanze in Rome). In altarpieces, by contrast, the narrative subsequently shrinks to a few incidents in the predella, allowing maximum emphasis on the central scene of the Virgin and Child or of the Crucifixion. Duccio's work contains elements of two styles which will later go their separate ways, each bringing results of great beauty. The chunky realistic quality which he shares (to a lesser degree) with Giotto reappears a century later in the work of Masaccio, leading to a strong native Italian tradition. Meanwhile a more refined and slender quality in some of Duccio's figures is developed by Simone Martini, the greatest Sienese painter of the next generation and possibly trained in Duccio's studio. Simone's Annunciation in the Uffizi is a good example of this refined style, which by the end of the 14th century is popular throughout Europe - becoming known later as International Gothic.
to be continued………………
The History of Motion Pictures:06
(after last publication)
Filmic effects
Unique amongst all the one minute long films made by the Edison company, which recorded parts of the acts of variety performers for their Kinetoscope viewing machines, was The Execution of Mary, Queen of Scots. This showed a person dressed as the queen placing her head on the execution block in front of a small group of bystanders in Elizabethan dress. The executioner brings his axe down, and the queen's severed head drops onto the ground. This trick was worked by stopping the camera and replacing the actor with a dummy, then restarting the camera before the axe falls. The two pieces of film were then trimmed and cemented together so that the action appeared continuous when the film was shown.
This film was among those exported to Europe with the first Kinetoscope machines in 1895, and was seen by Georges Méliès, who was putting on magic shows in his Theatre Robert-Houdin in Paris at the time. He took up film-making in 1896, and after making imitations of other films from Edison, Lumière, and Robert Paul, he made Escamotage d’un dame chez Robert-Houdin (The Vanishing Lady). This film shows a woman being made to vanish by using the same stop motion technique as the earlier Edison film. After this, Georges Méliès made many single shot films using this trick over the next couple of years.
The other basic set of techniques for trick cinematography involves double exposure of the film in the camera, which was first done by G.A. Smith in July 1898 in England. His The Corsican Brothers was described in the catalogue of the Warwick Trading Company, which took up the distribution of Smith's films in 1900, thus:
“One of the twin brothers returns home from shooting in the Corsican mountains, and is visited by the ghost of the other twin. By extremely careful photography the ghost appears *quite transparent*. After indicating that he has been killed by a sword-thrust, and appealing for vengeance, he disappears. A ‘vision’ then appears showing the fatal duel in the snow. To the Corsican's amazement, the duel and death of his brother are vividly depicted in the vision, and finally, overcome by his feelings, he falls to the floor just as his mother enters the room.”
The ghost effect was simply done by draping the set in black velvet after the main action had been shot, and then re-exposing the negative with the actor playing the ghost going through the actions at the appropriate point. Likewise, the vision, which appeared within a circular vignette or matte, was similarly superimposed over a black area in the backdrop to the scene, rather than over a part of the set with detail in it, so that nothing appeared through the image, which seemed quite solid. Smith used this technique again a year later in Santa Claus.
Georges Méliès first used superimposition on a dark background in la Caverne maudite (The Cave of the Demons) made a couple of months later in 1898, and then elaborated it further with multiple superimpositions in the one shot in l’Homme de têtes (The Troublesome Heads). He then did it with further variations in numerous subsequent films.
Other special techniques
The other special effect technique that G.A. Smith initiated was reverse motion. He did this by repeating the action a second time, while filming it with an inverted camera, and then joining the tail of the second negative to that of the first. The first films made using this device were Tipsy, Topsy, Turvy and The Awkward Sign Painter. The Awkward Sign Painter showed a sign painter lettering a sign, and in the reverse printing of the same footage appended to the standard print, the painting on the sign vanished under the painter's brush. The earliest surviving example of this technique is Smith's The House That Jack Built, made before September 1900. Here, a small boy is shown knocking down a castle just constructed by a little girl out of children's building blocks. Then a title appears, saying “Reversed”, and the action is repeated in reverse, so that the castle re-erects itself under his blows.
Hepworth took this technique further, by printing the negative of the forwards motion backwards frame by frame, so producing a print in which the original action was exactly reversed. To do this he built a special printer in which the negative running through a projector was projected into the gate of a camera through a special lens giving a same-size image. This arrangement came to be called a “projection printer”, and eventually an “optical printer”. With it Hepworth made The Bathers in 1900, in which bathers who have undressed and jumped into the water appear to spring backwards out of it, and have their clothes magically fly back onto their bodies.
The use of different camera speeds also appeared around 1900. To make Robert Paul's On a Runaway Motor Car through Piccadilly Circus (1899), the camera was turned very slowly, so that when the film was projected at the usual 16 frames per second, the scenery appeared to be passing at great speed. Cecil Hepworth used the opposite effect in The Indian Chief and the Seidlitz Powder (1901), in which a naïve Red Indian eats a lot of the fizzy stomach medicine, causing his stomach to expand vastly. He leaps around in a way that is made balloon-like by cranking the camera much faster than 16 frames per second. This gives what we would call a “slow motion” effect.
Animation
The most important development in this area of special techniques did not happen until 1905, when Edwin Porter made How Jones Lost His Roll, and The Whole Dam Family and the Dam Dog. Both of these films had intertitles which were formed by the letters moving into place from a random scattering to form the words of the titles. This was done by exposing the film one frame at a time, and moving the letters a little bit towards their final position between each exposure. This is what has come to be called “single frame animation” or “object animation”, and it needs a slightly adapted camera that exposes only one frame for each turn of the crank handle, rather than the usual eight frames per turn.
In 1906, Albert Edward Smith and James Stuart Blackton at Vitagraph took the next step, and in their Humorous Phases of Funny Faces, what appear to be cartoon drawings of people move from one pose to another. This is done for most of the length of this film by moving jointed cut-outs of the figures frame by frame between the exposures, just as Porter moved his letters. However, there is a very short section of the film where things are made to appear to move by altering the drawings themselves from frame to frame, which is how standard animated cartoons have since been made up to today.
to be continued………………
Filmic effects
Unique amongst all the one minute long films made by the Edison company, which recorded parts of the acts of variety performers for their Kinetoscope viewing machines, was The Execution of Mary, Queen of Scots. This showed a person dressed as the queen placing her head on the execution block in front of a small group of bystanders in Elizabethan dress. The executioner brings his axe down, and the queen's severed head drops onto the ground. This trick was worked by stopping the camera and replacing the actor with a dummy, then restarting the camera before the axe falls. The two pieces of film were then trimmed and cemented together so that the action appeared continuous when the film was shown.
This film was among those exported to Europe with the first Kinetoscope machines in 1895, and was seen by Georges Méliès, who was putting on magic shows in his Theatre Robert-Houdin in Paris at the time. He took up film-making in 1896, and after making imitations of other films from Edison, Lumière, and Robert Paul, he made Escamotage d’un dame chez Robert-Houdin (The Vanishing Lady). This film shows a woman being made to vanish by using the same stop motion technique as the earlier Edison film. After this, Georges Méliès made many single shot films using this trick over the next couple of years.
The other basic set of techniques for trick cinematography involves double exposure of the film in the camera, which was first done by G.A. Smith in July 1898 in England. His The Corsican Brothers was described in the catalogue of the Warwick Trading Company, which took up the distribution of Smith's films in 1900, thus:
“One of the twin brothers returns home from shooting in the Corsican mountains, and is visited by the ghost of the other twin. By extremely careful photography the ghost appears *quite transparent*. After indicating that he has been killed by a sword-thrust, and appealing for vengeance, he disappears. A ‘vision’ then appears showing the fatal duel in the snow. To the Corsican's amazement, the duel and death of his brother are vividly depicted in the vision, and finally, overcome by his feelings, he falls to the floor just as his mother enters the room.”
The ghost effect was simply done by draping the set in black velvet after the main action had been shot, and then re-exposing the negative with the actor playing the ghost going through the actions at the appropriate point. Likewise, the vision, which appeared within a circular vignette or matte, was similarly superimposed over a black area in the backdrop to the scene, rather than over a part of the set with detail in it, so that nothing appeared through the image, which seemed quite solid. Smith used this technique again a year later in Santa Claus.
Georges Méliès first used superimposition on a dark background in la Caverne maudite (The Cave of the Demons) made a couple of months later in 1898, and then elaborated it further with multiple superimpositions in the one shot in l’Homme de têtes (The Troublesome Heads). He then did it with further variations in numerous subsequent films.
Other special techniques
The other special effect technique that G.A. Smith initiated was reverse motion. He did this by repeating the action a second time, while filming it with an inverted camera, and then joining the tail of the second negative to that of the first. The first films made using this device were Tipsy, Topsy, Turvy and The Awkward Sign Painter. The Awkward Sign Painter showed a sign painter lettering a sign, and in the reverse printing of the same footage appended to the standard print, the painting on the sign vanished under the painter's brush. The earliest surviving example of this technique is Smith's The House That Jack Built, made before September 1900. Here, a small boy is shown knocking down a castle just constructed by a little girl out of children's building blocks. Then a title appears, saying “Reversed”, and the action is repeated in reverse, so that the castle re-erects itself under his blows.
Hepworth took this technique further, by printing the negative of the forwards motion backwards frame by frame, so producing a print in which the original action was exactly reversed. To do this he built a special printer in which the negative running through a projector was projected into the gate of a camera through a special lens giving a same-size image. This arrangement came to be called a “projection printer”, and eventually an “optical printer”. With it Hepworth made The Bathers in 1900, in which bathers who have undressed and jumped into the water appear to spring backwards out of it, and have their clothes magically fly back onto their bodies.
The use of different camera speeds also appeared around 1900. To make Robert Paul's On a Runaway Motor Car through Piccadilly Circus (1899), the camera was turned very slowly, so that when the film was projected at the usual 16 frames per second, the scenery appeared to be passing at great speed. Cecil Hepworth used the opposite effect in The Indian Chief and the Seidlitz Powder (1901), in which a naïve Red Indian eats a lot of the fizzy stomach medicine, causing his stomach to expand vastly. He leaps around in a way that is made balloon-like by cranking the camera much faster than 16 frames per second. This gives what we would call a “slow motion” effect.
Animation
The most important development in this area of special techniques did not happen until 1905, when Edwin Porter made How Jones Lost His Roll, and The Whole Dam Family and the Dam Dog. Both of these films had intertitles which were formed by the letters moving into place from a random scattering to form the words of the titles. This was done by exposing the film one frame at a time, and moving the letters a little bit towards their final position between each exposure. This is what has come to be called “single frame animation” or “object animation”, and it needs a slightly adapted camera that exposes only one frame for each turn of the crank handle, rather than the usual eight frames per turn.
In 1906, Albert Edward Smith and James Stuart Blackton at Vitagraph took the next step, and in their Humorous Phases of Funny Faces, what appear to be cartoon drawings of people move from one pose to another. This is done for most of the length of this film by moving jointed cut-outs of the figures frame by frame between the exposures, just as Porter moved his letters. However, there is a very short section of the film where things are made to appear to move by altering the drawings themselves from frame to frame, which is how standard animated cartoons have since been made up to today.
to be continued………………
Wednesday, August 6, 2008
Rhythm of Clouds:
Making Photographs:04
a textbook by Philip Greenspun; revised January 2007
(after last publication)
More elaborate recommendations for a wider variety of light conditions can be found in the Kodak Professional Photo Guide.
How well does it work to simply read Kodak's instructions and follow them as best you can? Quite well with negative film; not well enough with slide film; not at all when using electronic flash.
Fundamentally, an exposure meter can be built in two ways. The first is to measure the light falling on the subject that you intend to photograph: incident metering. The second is to measure the light coming off the subject in the direction of the camera lens: reflected metering. The typical handheld accessory lightmeter gives the photographer a choice between these two methods. The typical in-camera meter can only measure reflected light. Both kinds of meters recommend a combination of aperture and shutter speed to the photographer who will then use that recommendation as a starting point when actually exposing film.
When using an incident light meter, the most important source of error of which the photographer must be aware occurs when the light is highly directional. The incident dome may not catch the light exactly the way the combination of the subject and camera lens.
When using a reflected light meter, the most important source of error is that the subject's reflectance may not match the meter's assumption about the subject's reflectance. Suppose that you're taking individual portraits of Alex and Mia (at right). You measure the light being reflected off Alex's white fur and set the camera to whatever the meter recommends. Repeating the image with Mia as the subject you find that much less light is reflected by her black and brown fur. So the reflected light meter recommends a wider aperture or a slower shutter speed than it did for Alex.
Does this make sense? With negative film, perhaps. Mia is darker and if you want to get her tones into the linear portion of the film's curve you'll need a longer exposure. But consider that if you'd used an incident light meter it would have recommended the same exposure for both dogs. After all, the same amount of light was falling on them. If you'd used color slide film and the incident meter's recommendation you'd get one slide with a white dog in it and one slide with a black dog in it. What if you'd used the reflected meter's recommendation with the slide film? You'd get two slides exposed with an identical amount of light and therefore both would be the same shade.
Exactly what shade do you get when you follow a reflective meter's recommendation? 18% gray. This is a tone midway between 0% gray (white) and 100% gray (black). Reflected meters are calibrated to assume that the average scene is 18% gray. The reflected meter couldn't know that Alex is a white dog and that Mia is a black dog. When you pointed it at Alex it assumed that the day had gotten brighter. When you pointed it at Mia it assumed that the sky had become cloudier.
Is this 18% gray assumption reasonable? If you take portraits of Caucasian people and meter off their facial skin you'll probably find that your slides come out a bit too dark. Typical Caucasian skin is about 1/2 f-stop lighter than 18% gray. So the reflected meter thinks that the subject is lit somewhat brighter than in reality.
Painful Details
There are some details that can make life painful when setting exposure. As you focus closer to a subject you are moving the lens farther from the film. The lens is throwing the same amount of light in a larger and larger circle of which the film intercepts a smaller and smaller fraction. For small format (35mm) cameras this effect is not significant until you get a macro lens and start taking pictures of things comparable in size to the 24x36mm frame itself. However, if you are taking macro photographs and following the recommendations of a handheld light meter you will find that your pictures are underexposed by 1 or 2 f-stops.
The handheld meter, whether reflected or incident, can't know what impediments there are to light reaching the film. The meter manufacturers assume an ideal lens. Your lens may be covered with a fine coating of dust. Your lens's internal elements will not be perfectly transmissive; some light will be lost each time it goes through a piece of glass within your lens. You may have stuck a filter in front of the lens.
A good way of sweeping away all of these details is the through-the-lens meter. Necessarily a reflected light meter, the metering cells are placed behind the lens and in front of the film, oftentimes built into the viewing system. These cells see what the film will see and therefore if light is getting blocked for any reason the meter simply sets the exposure as if there were less overall scene illumination.
Digital Cameras:
We've arrived at the last and least important chapter in the text.Your choice of camera will not have much effect on the final image. If you're going to be a working photographer, however, you should know what tools are available.
Here are the factors that go into the choice of a camera for a project:
1. What is the required final image quality?
2. At what magnification will the image be viewed?
3. How much weight can you carry to the subject?
4. How much time do you have to take the picture?
Suppose that your project demands high image quality and high magnification. For example, you are going to make a 40 x 60 inch enlargement and display it in a corridor where people can walk right up to it to check out fine detail. This requirement pushes you toward using high resolution high quality sensor for the original exposure. That high-res, high-quality sensor may come wrapped in a large relatively heavy camera, which gets us into Factor 3: "How much weight can you carry to the subject?"
Different cameras work at different speeds. With the latest Canon or Nikon autofocus systems, you might be able to capture an unanticipated event on a soccer field. A photographer using a view camera and digital back will not be able to do this; he will still be setting up the tripod, focusing, stopping the lens down to taking aperture, closing the shutter, cocking the shutter, attaching a laptop computer, etc. If your subject is a big mountain, you can probably afford to take your time making the image.
Now that we have the factors in mind, let's dive into the types of cameras available:
(after last publication)
More elaborate recommendations for a wider variety of light conditions can be found in the Kodak Professional Photo Guide.
How well does it work to simply read Kodak's instructions and follow them as best you can? Quite well with negative film; not well enough with slide film; not at all when using electronic flash.
Fundamentally, an exposure meter can be built in two ways. The first is to measure the light falling on the subject that you intend to photograph: incident metering. The second is to measure the light coming off the subject in the direction of the camera lens: reflected metering. The typical handheld accessory lightmeter gives the photographer a choice between these two methods. The typical in-camera meter can only measure reflected light. Both kinds of meters recommend a combination of aperture and shutter speed to the photographer who will then use that recommendation as a starting point when actually exposing film.
When using an incident light meter, the most important source of error of which the photographer must be aware occurs when the light is highly directional. The incident dome may not catch the light exactly the way the combination of the subject and camera lens.
When using a reflected light meter, the most important source of error is that the subject's reflectance may not match the meter's assumption about the subject's reflectance. Suppose that you're taking individual portraits of Alex and Mia (at right). You measure the light being reflected off Alex's white fur and set the camera to whatever the meter recommends. Repeating the image with Mia as the subject you find that much less light is reflected by her black and brown fur. So the reflected light meter recommends a wider aperture or a slower shutter speed than it did for Alex.
Does this make sense? With negative film, perhaps. Mia is darker and if you want to get her tones into the linear portion of the film's curve you'll need a longer exposure. But consider that if you'd used an incident light meter it would have recommended the same exposure for both dogs. After all, the same amount of light was falling on them. If you'd used color slide film and the incident meter's recommendation you'd get one slide with a white dog in it and one slide with a black dog in it. What if you'd used the reflected meter's recommendation with the slide film? You'd get two slides exposed with an identical amount of light and therefore both would be the same shade.
Exactly what shade do you get when you follow a reflective meter's recommendation? 18% gray. This is a tone midway between 0% gray (white) and 100% gray (black). Reflected meters are calibrated to assume that the average scene is 18% gray. The reflected meter couldn't know that Alex is a white dog and that Mia is a black dog. When you pointed it at Alex it assumed that the day had gotten brighter. When you pointed it at Mia it assumed that the sky had become cloudier.
Is this 18% gray assumption reasonable? If you take portraits of Caucasian people and meter off their facial skin you'll probably find that your slides come out a bit too dark. Typical Caucasian skin is about 1/2 f-stop lighter than 18% gray. So the reflected meter thinks that the subject is lit somewhat brighter than in reality.
Painful Details
There are some details that can make life painful when setting exposure. As you focus closer to a subject you are moving the lens farther from the film. The lens is throwing the same amount of light in a larger and larger circle of which the film intercepts a smaller and smaller fraction. For small format (35mm) cameras this effect is not significant until you get a macro lens and start taking pictures of things comparable in size to the 24x36mm frame itself. However, if you are taking macro photographs and following the recommendations of a handheld light meter you will find that your pictures are underexposed by 1 or 2 f-stops.
The handheld meter, whether reflected or incident, can't know what impediments there are to light reaching the film. The meter manufacturers assume an ideal lens. Your lens may be covered with a fine coating of dust. Your lens's internal elements will not be perfectly transmissive; some light will be lost each time it goes through a piece of glass within your lens. You may have stuck a filter in front of the lens.
A good way of sweeping away all of these details is the through-the-lens meter. Necessarily a reflected light meter, the metering cells are placed behind the lens and in front of the film, oftentimes built into the viewing system. These cells see what the film will see and therefore if light is getting blocked for any reason the meter simply sets the exposure as if there were less overall scene illumination.
Digital Cameras:
We've arrived at the last and least important chapter in the text.Your choice of camera will not have much effect on the final image. If you're going to be a working photographer, however, you should know what tools are available.
Here are the factors that go into the choice of a camera for a project:
1. What is the required final image quality?
2. At what magnification will the image be viewed?
3. How much weight can you carry to the subject?
4. How much time do you have to take the picture?
Suppose that your project demands high image quality and high magnification. For example, you are going to make a 40 x 60 inch enlargement and display it in a corridor where people can walk right up to it to check out fine detail. This requirement pushes you toward using high resolution high quality sensor for the original exposure. That high-res, high-quality sensor may come wrapped in a large relatively heavy camera, which gets us into Factor 3: "How much weight can you carry to the subject?"
Different cameras work at different speeds. With the latest Canon or Nikon autofocus systems, you might be able to capture an unanticipated event on a soccer field. A photographer using a view camera and digital back will not be able to do this; he will still be setting up the tripod, focusing, stopping the lens down to taking aperture, closing the shutter, cocking the shutter, attaching a laptop computer, etc. If your subject is a big mountain, you can probably afford to take your time making the image.
Now that we have the factors in mind, let's dive into the types of cameras available:
- point and shoot (subject of a separate article)
- single-lens reflex (SLR) cameras; the standard mass-market tool
- lens-shutter and rangefinder cameras; great values, terrible values, and nothing in between
- digital backs for medium-format and view cameras
- panoramic cameras
Sensor Sizes
Larger sensors offer lower noise at high ISO settings and are therefore essential for taking pictures in low light conditions. The best light for photography is typically fairly dim and therefore using a larger sensor is highly desirable. Unfortunately, the cost of manufacturing a sensor goes up exponentially with size and the largest sensors can cost more than a car. Here are the standard sizes:
1/1.8": 5x7mm, common size for point and shoot cameras
4/3": 13.5x18mm, the Olympus Four Thirds system- APS-C: 15.7x23.7mm, the standard for "small sensor" digital SLRs such as the Nikon D200, $1289 and Canon Digital Rebel XTi (Black), $545
35mm film: 24x36mm, Canon's better digital SLRs, starting with the Canon EOS 5D, $1890- 48x36mm, Hasselblad H3D and digital backs from companies such as Leaf, MegaVision, Phase One, Sinar
60mm line, scanning backs from Seitz
72x96mm, scanning backs from BetterLight
The scanning back, a line of CCD elements that are swept mechanically behind the lens, is a great idea, but it only works for static subjects since the minimum scan time is about one second.
to be continued………………
History of painting: 04
(after last publication)
Illuminated manuscripts: 7th - 11th century AD
Irish monks of the 7th and 8th century create illuminated manuscripts which are among the greatest treasures of Celtic and early Christian art. The beautiful calligraphy (the scribes sometimes add complaints in the margin about their difficult working conditions) usually provides the text of the four Gospels. The earliest is the Book of Durrow, from about 650. Others include the Lindisfarne Gospels (c.700) and the Book of Kells (c.800). The glory of these manuscripts (in addition to their wonderfully inventive images of the evangelists) is the intricate decoration, with the famous 'carpet pages' formed of interlacing patterns - reminiscent of the complex linear designs in Celtic metalwork.
In the late 8th century many illuminated manuscripts are commissioned by Charlemagne, who values them both as holy objects and as his own personal art gallery. When the imperial court is on the move (which is most of the time), part of the emperor's baggage train is a wagon full of precious manscripts. Legend adds that after his death Charlemagne is buried in a sitting position, clothed in rich robes and holding a sceptre. On his lap is an illuminated manuscript. The scribes writing the texts of the manuscripts, and the illuminators adding the decorative lettering and the illustrations, do so in the workshops of Europe's monasteries - though probably not all the men employed are monks. The example of Charlemagne's patronage is followed by his immediate successors and by later rulers in medieval Europe, in particular by the emperors of the Ottonian dynasty.
The Carolingian and Ottonian manuscripts are usually gospels or other holy texts, but the secular world intrudes more than previously. A frontispiece often now shows the imperial patron on his throne, in a manner previously reserved for Jesus or one of the evangelists. The early medieval interest in illuminated manuscripts means that the portable art of the period is confined within precious volumes. A single spread of text, with ornament and illustration, is sometimes visible today in museum displays. But for the most part these images are locked away on the rare-book shelves of libraries. This seclusion has preserved them in better condition than other art of the same period, but it has also had the effect of making this a somewhat invisible chapter in the story of European painting. The artists begin to achieve a higher profile, from the 13th century, with fresco painting in Italy.
Buddhist banners and scrolls on silk: from the 9th c. AD
The cave discovered in 1899 at Dunhuang contains many Buddhist paintings on silk. The larger ones (mostly showing Buddha seated in paradise with attendant figures) are designed for hanging out on poles on special occasions. Some are almost two yards in height and more than a yard wide. Narrower vertical images of dramatically painted figures from Buddhist mythology are intended as banners, to be carried in procession with silk streamers attached. Painting on silk remains a central theme of Chinese art.
But this flamboyant public use of images, characteristic of Buddhism, subsequently gives way to the more discreet and private art of the Confucians.
Chinese arts: in the Song dynasty
In the heyday of classical Chinese culture, a civilized gentleman - meaning a Confucian official - should be adept in three different artistic fields. When he settles down before a fresh sheet of paper and dips his brush in the ink (ground from a block of pigment by a servant), no one can be certain whether he is about to pen an impromptu poem, paint a quick impression of a romantic landscape or fashion some traditional phrase in exquisite Chinese characters.
The three skills, all expressed in the beauty of brush strokes, are closely linked. A 'soundless poem' is a conventional Chinese term for a picture. And a typical poem by the Song master Ou-yang Hsiu sounds like a painting.
Poetry and painting in Song China (960-1279) are largely social activities, both in the creation and in the appreciation of the work. On a convivial occasion, with wine flowing, Confucians will compete with each other in writing or painting. In more sober vein, among connoisseurs, a collector will bring the scrolls from their boxes and will unroll them to be admired and discussed. China's past is also now a theme for conoisseurs, in a fashion pioneered by Ou-yang Hsiu (and echoed centuries later in Italy during the Renaissance).
Ou-yang Hsiu clambers 'on precarious cliffs and inaccessible gorges, in wild forests and abandoned tombs' to make rubbings which he publishes, in about 1000 portfolios, as his Collection of Ancient Inscriptions'. Inevitably much of the painting done by enthusiastic amateurs is dull and conventional. This is particularly true during the reign of the emperor Hui Tsung. Himself a talented painter, of a carefully exact kind, he sets up an official academy of painting. Those who want to get on at court are unlikely to disagree with the emperor on matters of artistic style. Others, opting out of the system, come under the influence of Chan or Zen Buddhism with its emphasis on freedom of expression.
The Chan painters of the Song dynasty, using a few quick brushstrokes to capture a fleeting visual moment, provide one of the most brilliant interludes in the story of Chinese art.
European frescoes: 10th - 13th century AD
Although the grandest style of medieval church decoration is mosaic, the classical tradition of painted murals (as at Pompeii or in the catacombs) continues to be used. A surviving example is the 10th-century church of St George at Oberzell, on the island of Reichenau in Lake Constance. The frescoes here, depicting the miracles of Christ, are painted in a strip high above the rows of columns and rounded arches which flank the nave. The rather remote position of the images is exactly that of the Old Testament scenes depicted in mosaic five centuries earlier in the church of Santa Maria Maggiore in Rome.
Frescoes are more vulnerable than mosaic, and many more fresco cycles were painted in the Middle Ages than have survived. But the preferred medium for important church interiors continues to be mosaic in the Byzantine style - even as late as the end of the 13th century, when the gilded narrative panels are set into the dome of the baptistery in Florence. But at exactly the same period elsewhere in central Italy, at Assisi, an important new building is being decorated entirely in fresco. It is the convent church of St Francis. Built on a hillside, and consisting of two basilicas one above the other, its construction begins soon after the saint's death in 1226.
Assisi attracts thousands of pilgrims. The frescoes depicting the life of St Francis are for their edification. Instead of being high in the air above the arches of the nave, these images are now close to ground level. Unlike the earlier Romanesque interiors, the pointed Gothic arches reach right up to the vaulting of the roof. The top half of the arch can become the window, while the lower part is closed in to provide a flat wall for the painted images. In this design of church the frescoes are close enough to the onlooker for the painter to be able to tell a detailed story. Work on the Assisi frescoes begins in about 1280, probably under the supervision of Cimabue - considered by his contemporaries the greatest Italian master.
The scenes of the life of St Francis in the upper church are painted with a much greater sense of realism and drama than has been the case with Byzantine mosaics. Some of these scenes are almost certainly the work, during the 1290s, of the first great genius to use the medium of fresco - Giotto. In the next decade Giotto decorates almost entirely with his own hand an entire chapel in Padua.
to be continued………………
Illuminated manuscripts: 7th - 11th century AD
Irish monks of the 7th and 8th century create illuminated manuscripts which are among the greatest treasures of Celtic and early Christian art. The beautiful calligraphy (the scribes sometimes add complaints in the margin about their difficult working conditions) usually provides the text of the four Gospels. The earliest is the Book of Durrow, from about 650. Others include the Lindisfarne Gospels (c.700) and the Book of Kells (c.800). The glory of these manuscripts (in addition to their wonderfully inventive images of the evangelists) is the intricate decoration, with the famous 'carpet pages' formed of interlacing patterns - reminiscent of the complex linear designs in Celtic metalwork.
In the late 8th century many illuminated manuscripts are commissioned by Charlemagne, who values them both as holy objects and as his own personal art gallery. When the imperial court is on the move (which is most of the time), part of the emperor's baggage train is a wagon full of precious manscripts. Legend adds that after his death Charlemagne is buried in a sitting position, clothed in rich robes and holding a sceptre. On his lap is an illuminated manuscript. The scribes writing the texts of the manuscripts, and the illuminators adding the decorative lettering and the illustrations, do so in the workshops of Europe's monasteries - though probably not all the men employed are monks. The example of Charlemagne's patronage is followed by his immediate successors and by later rulers in medieval Europe, in particular by the emperors of the Ottonian dynasty.
The Carolingian and Ottonian manuscripts are usually gospels or other holy texts, but the secular world intrudes more than previously. A frontispiece often now shows the imperial patron on his throne, in a manner previously reserved for Jesus or one of the evangelists. The early medieval interest in illuminated manuscripts means that the portable art of the period is confined within precious volumes. A single spread of text, with ornament and illustration, is sometimes visible today in museum displays. But for the most part these images are locked away on the rare-book shelves of libraries. This seclusion has preserved them in better condition than other art of the same period, but it has also had the effect of making this a somewhat invisible chapter in the story of European painting. The artists begin to achieve a higher profile, from the 13th century, with fresco painting in Italy.
Buddhist banners and scrolls on silk: from the 9th c. AD
The cave discovered in 1899 at Dunhuang contains many Buddhist paintings on silk. The larger ones (mostly showing Buddha seated in paradise with attendant figures) are designed for hanging out on poles on special occasions. Some are almost two yards in height and more than a yard wide. Narrower vertical images of dramatically painted figures from Buddhist mythology are intended as banners, to be carried in procession with silk streamers attached. Painting on silk remains a central theme of Chinese art.
But this flamboyant public use of images, characteristic of Buddhism, subsequently gives way to the more discreet and private art of the Confucians.
Chinese arts: in the Song dynasty
In the heyday of classical Chinese culture, a civilized gentleman - meaning a Confucian official - should be adept in three different artistic fields. When he settles down before a fresh sheet of paper and dips his brush in the ink (ground from a block of pigment by a servant), no one can be certain whether he is about to pen an impromptu poem, paint a quick impression of a romantic landscape or fashion some traditional phrase in exquisite Chinese characters.
The three skills, all expressed in the beauty of brush strokes, are closely linked. A 'soundless poem' is a conventional Chinese term for a picture. And a typical poem by the Song master Ou-yang Hsiu sounds like a painting.
Poetry and painting in Song China (960-1279) are largely social activities, both in the creation and in the appreciation of the work. On a convivial occasion, with wine flowing, Confucians will compete with each other in writing or painting. In more sober vein, among connoisseurs, a collector will bring the scrolls from their boxes and will unroll them to be admired and discussed. China's past is also now a theme for conoisseurs, in a fashion pioneered by Ou-yang Hsiu (and echoed centuries later in Italy during the Renaissance).
Ou-yang Hsiu clambers 'on precarious cliffs and inaccessible gorges, in wild forests and abandoned tombs' to make rubbings which he publishes, in about 1000 portfolios, as his Collection of Ancient Inscriptions'. Inevitably much of the painting done by enthusiastic amateurs is dull and conventional. This is particularly true during the reign of the emperor Hui Tsung. Himself a talented painter, of a carefully exact kind, he sets up an official academy of painting. Those who want to get on at court are unlikely to disagree with the emperor on matters of artistic style. Others, opting out of the system, come under the influence of Chan or Zen Buddhism with its emphasis on freedom of expression.
The Chan painters of the Song dynasty, using a few quick brushstrokes to capture a fleeting visual moment, provide one of the most brilliant interludes in the story of Chinese art.
European frescoes: 10th - 13th century AD
Although the grandest style of medieval church decoration is mosaic, the classical tradition of painted murals (as at Pompeii or in the catacombs) continues to be used. A surviving example is the 10th-century church of St George at Oberzell, on the island of Reichenau in Lake Constance. The frescoes here, depicting the miracles of Christ, are painted in a strip high above the rows of columns and rounded arches which flank the nave. The rather remote position of the images is exactly that of the Old Testament scenes depicted in mosaic five centuries earlier in the church of Santa Maria Maggiore in Rome.
Frescoes are more vulnerable than mosaic, and many more fresco cycles were painted in the Middle Ages than have survived. But the preferred medium for important church interiors continues to be mosaic in the Byzantine style - even as late as the end of the 13th century, when the gilded narrative panels are set into the dome of the baptistery in Florence. But at exactly the same period elsewhere in central Italy, at Assisi, an important new building is being decorated entirely in fresco. It is the convent church of St Francis. Built on a hillside, and consisting of two basilicas one above the other, its construction begins soon after the saint's death in 1226.
Assisi attracts thousands of pilgrims. The frescoes depicting the life of St Francis are for their edification. Instead of being high in the air above the arches of the nave, these images are now close to ground level. Unlike the earlier Romanesque interiors, the pointed Gothic arches reach right up to the vaulting of the roof. The top half of the arch can become the window, while the lower part is closed in to provide a flat wall for the painted images. In this design of church the frescoes are close enough to the onlooker for the painter to be able to tell a detailed story. Work on the Assisi frescoes begins in about 1280, probably under the supervision of Cimabue - considered by his contemporaries the greatest Italian master.
The scenes of the life of St Francis in the upper church are painted with a much greater sense of realism and drama than has been the case with Byzantine mosaics. Some of these scenes are almost certainly the work, during the 1290s, of the first great genius to use the medium of fresco - Giotto. In the next decade Giotto decorates almost entirely with his own hand an entire chapel in Padua.
to be continued………………
The History of Motion Pictures:05
(after last publication)
Film exhibition
Initially films were mostly shown as a novelty in special venues, but the main methods of exhibition quickly became either as an item on the programmes of variety theatres, or by travelling showman in tent theatres, which they took around the fairs in country towns. It became the practice for the producing companies to sell prints outright to the exhibitors, at so much per foot, regardless of the subject. Typical prices initially were 15 cents a foot in the United States, and one shilling a foot in Britain. Hand-coloured films, which were being produced of the most popular subjects before 1900, cost 2 to 3 times as much per foot. There were a few producers, such as the American Mutoscope and Biograph Company, which did not sell their films, but exploited them solely with their own exhibition units. The first successful permanent theatre showing nothing but films was “The Nickelodeon”, which was opened in Pittsburgh in 1905. By this date there were finally enough films several minutes long available to fill a programme running for at least half an hour, and which could be changed weekly when the local audience became bored with it. Other exhibitors in the United States quickly followed suit, and within a couple of years there were thousands of these nickelodeons in operation. The American situation led to a world-wide boom in the production and exhibition of films from 1906 onwards.
Film technique
Film exhibition
Initially films were mostly shown as a novelty in special venues, but the main methods of exhibition quickly became either as an item on the programmes of variety theatres, or by travelling showman in tent theatres, which they took around the fairs in country towns. It became the practice for the producing companies to sell prints outright to the exhibitors, at so much per foot, regardless of the subject. Typical prices initially were 15 cents a foot in the United States, and one shilling a foot in Britain. Hand-coloured films, which were being produced of the most popular subjects before 1900, cost 2 to 3 times as much per foot. There were a few producers, such as the American Mutoscope and Biograph Company, which did not sell their films, but exploited them solely with their own exhibition units. The first successful permanent theatre showing nothing but films was “The Nickelodeon”, which was opened in Pittsburgh in 1905. By this date there were finally enough films several minutes long available to fill a programme running for at least half an hour, and which could be changed weekly when the local audience became bored with it. Other exhibitors in the United States quickly followed suit, and within a couple of years there were thousands of these nickelodeons in operation. The American situation led to a world-wide boom in the production and exhibition of films from 1906 onwards.
Film technique
Georges Méliès (left) painting a backdrop in his studio
The first movie cameras were fastened directly to the head of their tripod or other support, with only the crudest kind of levelling devices provided, in the manner of the still-camera tripod heads of the period. The earliest movie cameras were thus effectively fixed during the course of the shot, and hence the first camera movements were the result of mounting a camera on a moving vehicle. The first known of these was a film shot by a Lumière cameraman from the back platform of a train leaving Jerusalem in 1896, and by 1898 there were a number of films shot from moving trains. Although listed under the general heading of “panoramas” in the sales catalogues of the time, those films shot straight forward from in front of a railway engine were usually specifically referred to as “phantom rides”.
In 1897, Robert W. Paul had the first real rotating camera head made to put on a tripod, so that he could follow the passing processions of Queen Victoria's Diamond Jubilee in one uninterrupted shot. This device had the camera mounted on a vertical axis that could be rotated by a worm gear driven by turning a crank handle, and Paul put it on general sale the next year. Shots taken using such a "panning" head were also referred to as ‘panoramas’ in the film catalogues of the first decade of the cinema.
The standard pattern for early film studios was provided by the studio which Georges Méliès had built in May 1897. This had a glass roof and three glass walls constructed after the model of large studios for still photography, and it was fitted with thin cotton cloths that could be stretched below the roof to diffuse the direct rays of the sun on sunny days. The soft overall light without real shadows that this arrangement produced, and which also exists naturally on lightly overcast days, was to become the basis for film lighting in film studios for the next decade.
to be continued………………
The first movie cameras were fastened directly to the head of their tripod or other support, with only the crudest kind of levelling devices provided, in the manner of the still-camera tripod heads of the period. The earliest movie cameras were thus effectively fixed during the course of the shot, and hence the first camera movements were the result of mounting a camera on a moving vehicle. The first known of these was a film shot by a Lumière cameraman from the back platform of a train leaving Jerusalem in 1896, and by 1898 there were a number of films shot from moving trains. Although listed under the general heading of “panoramas” in the sales catalogues of the time, those films shot straight forward from in front of a railway engine were usually specifically referred to as “phantom rides”.
In 1897, Robert W. Paul had the first real rotating camera head made to put on a tripod, so that he could follow the passing processions of Queen Victoria's Diamond Jubilee in one uninterrupted shot. This device had the camera mounted on a vertical axis that could be rotated by a worm gear driven by turning a crank handle, and Paul put it on general sale the next year. Shots taken using such a "panning" head were also referred to as ‘panoramas’ in the film catalogues of the first decade of the cinema.
The standard pattern for early film studios was provided by the studio which Georges Méliès had built in May 1897. This had a glass roof and three glass walls constructed after the model of large studios for still photography, and it was fitted with thin cotton cloths that could be stretched below the roof to diffuse the direct rays of the sun on sunny days. The soft overall light without real shadows that this arrangement produced, and which also exists naturally on lightly overcast days, was to become the basis for film lighting in film studios for the next decade.
to be continued………………
Tuesday, August 5, 2008
Life and Landscape of Bangladesh:
This is the life of coastal area of Bangladesh. Facilities like education, health etc. are very limited………People have to struggle with life to survive ……..and very often they have to fight with fatal weather ……….
Making Photographs:03
a textbook by Philip Greenspun; revised January 2007
Exposure: (after last publication)
If you ask a professional for some exposure advice, the typical answer is "f/8 and be there." This is a bit of an in joke. The "f/8" part of it sounds vaguely technical and useful, since f/8 is an actual aperture that you can set on most lenses. But it doesn't mean anything without an accompanying shutter speed or film ISO. The "be there" reminds you that ultimately exposure is pretty easy. The most important thing to have is patience and dedication so that you're around when a great photograph is happening.
There is no correct exposure
As I noted in the chapter on film, the real world generally contains a wider range of tones than you can represent on paper, film, or even with the best digital sensors. You have to make an artistic decision about where you place those tones. Some detail will inevitably be lost as tones that are distinguishable in the real world are mapped to the same number out of a digital sensor or density on film.
This chapter will teach you how to control and predict which details are lost.
The Controls
Single-lens reflex cameras have an intimidating array of buttons. It will please you to know that there are only three controls that affect the imaged: focus, aperture, and shutter speed. The two controls that affect exposure are aperture and shutter speed.
Aperture
If neither the subject nor the camera are moving, the shutter speed is not very important. Aperture, however, affects the depth of field and therefore which portions of the image will be in focus.
What is aperture and why is it useful to change it? Aperture is the degree to which the iris or diaphragm inside the lens is opened. Lenses are designed for maximum light-gathering capability. The diaphragm is just like the iris in your eye; it can be closed or stopped down to block off a portion of the light coming through the lens. A lot of expense and weight went into making your lens fast or good at gathering light. Why would you want to throw away some of that capability away?
The first reason to stop down a lens is that the world might simply be too bright. If you're using high-speed (sensitive) film and have a slow shutter that must expose the film for at least 1/500th of a second, using a smaller aperture is the only way to prevent too much light from striking the film and overexposing it.
A more interesting reason is for aesthetic control of sharpness. Suppose the lens has a maximum aperture of f/2. The f-number is the lens length divided by the diameter of the aperture opening. So for a 100mm lens, this would be a 50mm opening. The depth of field will be shallow. Only the object on which you focussed will be sharp. Things closer or farther from the camera will be out of focus. The range of distances for which objects are acceptably sharp is called the "depth of field". Notice the word "acceptably" in the definition. What is acceptable in an 8x10 print viewed from across the room may not be acceptable in the same print viewed at arm's length. What is acceptable in an 8x10 print viewed at arm's length may not be acceptable in a 30x40 print viewed at arm's length.
If you want more objects in the scene to be acceptably focussed, you have to stop down the lens to a smaller aperture, e.g., f/16 or f/22. This nomenclature is a bit confusing at first for beginners because a smaller aperture means that the lens length divided by the aperture diameter gets larger, yielding a larger f-number. Even more confusing is the fact that lenses are calibrated with a strange succession of apertures: 1.4, 2.0, 2.8, 4.0, 5.6, 8.0, 11, 16, 22, 32, 45, 64. Each step represents a halving of the amount of light that comes through the lens. Why? The area of the aperture is proportional to half the diameter squared. So multiplying the f-number by the square root of 2 halves the amount of light coming through the lens.
With a long lens and a wide aperture, the depth of field is very narrow. Only those objects exactly at the focussed distance will be sharp. For example, here are a couple of images taken with a 600mm lens at f/4 or f/5.6:
Notice that only the birds are sharp and the backgrounds are soft. The effect may seem rather extreme given that f/4 and f/5.6 are not ordinarily considered super wide apertures. Depth of field is related to the absolute size of the aperture not the f-number (lens length divided by aperture diameter). A 600mm lens is a big honker and an f-number of 4 implies an aperture 150mm across. I.e., the depth of field at f/4 on a 600mm lens will be shallower than at f/1.0 on a 50mm lens.
One way to achieve overall image sharpness is to choose a composition where everything is roughly the same distance from the lens (50mm).
Another approach is to stop the lens down to a small aperture. Note here the leaves in the upper right corner of the frame and the trees at infinity. Both are sharp thanks to the f/16 aperture used on this 50mm lens.
If you're using a single-lens reflex camera, where what you see through the viewfinder is what the film will see after the mirror flips up, you might be confused at this point. You turn the aperture ring on the lens and the image remains just as bright in the viewfinder. Moreover, out of focus objects don't get any sharper as you stop down. You're using a lens with an automatic diaphragm, introduced in the 1960s. The lens will be stopped down by the camera an instant before exposure, just as the mirror is flipping up. If you're just viewing and composing pictures, the lens is kept wide open for maximum brightness. To see what the film will see, you press the depth of field preview button. This lets you visualize in the viewfinder the focus effects of stopping down the aperture but it takes some practice to adjust to the extreme dimming that occurs by f/11 or f/16.
Shutter Speed
For a given amount of exposure on the film, the shutter speed can be determined by the aperture that you set for aesthetic purposes. If you are taking a portrait and want to throw the background out of focus, choose a wide-open f/2.8 aperture. Suppose that implies a shutter speed of 1/125th of a second. If you change your mind and want to ensure that the background is sharp, stop down to f/22, 6 f-stops less light. The film will need to be exposed for 2^6 times as long. Two raised to the 6th power is 64 so you'll need a shutter speed of 1/2 second to achieve the same density of exposure on film.
A camera with built-in meter can do this calculation for you. Professional photographers most typically use an exposure mode called "aperture-priority autoexposure". The photographer picks the aperture and the camera picks the shutter speed. Does it matter what shutter speed the camera picks? Not as long as neither the camera nor subject is moving. If they are standing up, most subjects won't be able to hold acceptably still for the 1/2 second exposure mentioned above. The photographer will be advised to open the aperture until the shutter speed is 1/15th second or faster. If the photographer is handholding the camera, i.e., not using a tripod, the 1/15th of a second exposure will very likely result in an unacceptable amount of camera shake being recorded on film. When using a normal lens, the general rule is to use shutter speeds of 1/60th or faster. Longer lenses magnify the subject but they also magnify camera shake. The traditional rule for handheld photography is to use shutter speeds of at least 1/focal-length. So if you've got a 250mm lens you'd use shutter speeds of 1/250th or faster. You'll be well advised to use faster speeds if you intend to make big enlargements from your originals. You can get away with slower shutter speeds if you either (1) brace yourself against a solid object, (2) rest the camera/lens on a solid object, or (3) use a lens with electronic image stabilization.
There are sometimes aesthetic reasons to use different shutter speeds. If you are taking a picture of something moving and want to show the motion, you'll need a slowish shutter speed. If you're taking a picture of something moving and want to freeze the motion, you'll need a fastish shutter speed, the exact speed depending on the velocity with which your subject is moving and whether the direction of moving is towards the camera or sideways across the frame (note: the best way to freeze motion is with an electronic flash, which is actually a kind of strobe light; a cheap on-camera flash may have a duration as short as 1/30,000th of a second).
Help in Setting Aperture and Shutter Speed
Given the information and examples above you ought to have some idea of the aesthetic results you're trying to achieve. If you're interested in the blurring or stopping of motion on film, set the shutter speed first. If you're interested in what will be in focus, set the aperture first. If you can't get a combination that suits you, look for a different speed of film or put a neutral density filter over the lens to reduce the amount of light coming through without changing what is in focus.
How do you know that you're send the right number of photons through to the film so that your result won't be completely black (underexposed slide) or completely white (overexposed slide)? Old-timers using negative film would simply estimate the exposure from their experience, then fix up any minor errors in the darkroom. A somewhat more accurate technique is to RTFM. Here are the instructions included with Kodak Tri-X, a name shared by two confusingly different films (Tri-X Pan is ISO 400 and has good midtone separation; Tri-X Pan Professional is ISO 320 and has more highlight separation):
"Use the exposures in the table below for frontlighted subjects from 2 hours after sunrise to 2 hours before sunset."
| Lighting Conditions | Shutter Speed (Second) | |
| Tri-X Pan | Tri-X Pan | |
| Bright or Hazy Sun on Light Sand or Snow | 1/500 | 1/500 |
| Bright or Hazy Sun | 1/500 | 1/500 |
| Weak, Hazy Sun | 1/500 | 1/500 |
| Cloudy Bright | 1/500 | 1/500 |
| Heavy Overcast or | 1/500 | 1/500 |
| * Use f/5.6 at 1/500 for backlighted close-up subjects. | ||
to be continued………………
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