The study of quality photography is essentially the study of identifying and reducing photographic degradation. Film quality, lens quality, and exposure all contribute to overall clarity. It is important to identify photographic trouble spots and deal with them in order, starting with the worst ones. With KAP, it is easy to identify the worst problem; it is always camera movement.
There are several ways to minimize the effects of camera movement. Faster shutter speeds, short lenses, and a more stable platform. Shutter speeds of 1/2000 are commonly available with focal plane shutters (SLRs) and speeds of 1/500 are available with between lens shutters found on point and shoot cameras. Of course, faster shutter speed means a wider aperture (faster lens) or faster film; because, KAP photos are taken outdoors, lighting is generally not a problem.
Image degradation due to movement is also proportional to lens focal length. A 70 mm lens is twice as susceptible to movement as a 35 mm lens. Fortunately, compact cameras achieve their small size by the use of short, wide angle lenses, 35 mm being the norm. Most experienced KAP photographers prefer short lenses for the interesting perspective they provide; short lenses can also be used closer to the subject and require less altitude.
The most common way to stabilize a camera is to use a tripod and to add mass to the camera. KAP photographers must find other methods of stabilization. The two common methods of supporting KAP rigs are the pendulum and the picavet suspension systems. I will not describe them here, but will point out that currently, the most promising seems to be the picavet. Vibration is also a potential problem. When a length of kite line, under tension, is exposed to the wind, it begins to vibrate like a violin string; rubber insulators are very effective in reducing these vibrations. Rubber donuts used for hanging automotive mufflers can be held in place above and below the camera with the use of small wooden pins. Tires from toy cars have also been used.
Lens quality is often, but not always related to price. Most SLR cameras have very good optics. Two favorite compact cameras, for KAP, are the Olympus Epic Stylus (mju-II in Europe), and the Yashica T4 (T5 in Europe.) Lens quality is also effected by aperture; it is a good rule of thumb that the lens performs best when stopped down 2 or 3 stops from its maximum aperture.
Back to TopThe finest grain film (low ASA rating) generally produces the clearest pictures. Normally, this means 100 ASA film, which is usually the slowest film speed available, although some film is available as slow as ASA 25. Black and white film generally has finer grain than color film, however color images have visual cues that help the viewer identify details more easily.
Contrast is the ability of a photographic system (film and paper) to reproduce a broad range of shades from dark to light. Careful control of contrast is especially important when photographing in bright sunlight. Photographers want dark regions of a subject to appear as black on their final print, and bright regions to appear as white. As it turns out, this is not always easy to do because the range of lighting on a sunny day is many times greater than the range of brightness that can be reproduced on a single piece of paper. Observant photographers will often note that subtle detail is recorded in the light and dark areas of a negative that cannot be reproduced onto photographic paper. In order to reproduce a range of brightness in a contrasty (sunny) scene, it is necessary to reduce the contrast as much as possible by selecting a film with low contrast; most professional films fall into this category, most color enhanced consumer films do not. I use Kodak PORTA 160 NC, Fugicolor Reala 100, or Fugicolor NPS 160 for photographing sailboats in bright sun. It is also possible to reduce contrast further by overexposing by 1 or 2 stops and having the photo lab "pull" the film by 1 or 2 stops during development. Pulling consists of reducing the development time and is the opposite of pushing. Go to a real photo lab; Wal-Mart won't be able to do this.
Latitude is the ability of film to handle under and over exposure. The rule of thumb is that it is better to overexpose than to underexpose. Overexposure can be corrected quite well during printing and is done automatically by printing machines. Print films have much better latitude than slide film. Low contrast films have better latitude than high contrast films.
Back to TopThere are a set of issues that are unique to KAP photographers. These issues influence camera choice in subtle ways. It is unlikely that any one rig will meet all of these requirements.
Format: Experience shows us that photographs that are enlarged too much have a grainy appearance. Intuition would tell us that enlargements made from larger negatives would yield better prints, however there is a problem to this logic that is unique to KAP. When a larger negative is used, a proportionately longer lens is required as well; a 4x5 negative requires a 150 mm lens to give the same perspective as a 35 mm lens on 35 mm film. If both cameras are tripod mounted, the 4x5 negative will give spectacularly better results than the 35 mm, but when the cameras are mounted on a moving platform, this performance is completely negated because the 150 mm lens is over 4 times more sensitive to motion than the 35 mm lens. 35mm cameras and film are cheap and light. There is no reason to go to a larger format. None!
Flash is unnecessary: Some KAP photographers like to see the flash to confirm the remote shutter release is working, but flash is very hard on camera battery life. Flash equipment and batteries add additional weight.
Automatic focus is unnecessary: When taking pictures into the wind, there is a danger that the camera will focus on the kite line. In KAP, the camera should almost always be focused at infinity. It is difficult to get a quality camera nowadays without automatic focus, but many allow you to turn it off. Set your camera on manual focus and tape the lens to infinity (or slightly less than infinity if your subject is close).
Make sure that your camera does not turn itself off under any conditions. Auto off is usually advertised as a good thing, but you should avoid it like the plague.
Zoom is unnecessary: It adds weight, complexity, and cost. Zoom lenses always have smaller apertures than fixed lenses.
Shutter priority is an automatic exposure mode that allows the photographer to select the shutter speed and the camera automatically selects the aperture to make a correct exposure. This mode is exactly what the KAP photographer needs, unfortunately, shutter priority is currently unavailable on compact point and shoot cameras.
Automatic winding: Not absolutely necessary, but so widely available on modern compact cameras, there is no good reason not to have this feature.
Electronic shutter release: This allows the camera to be triggered without the use of a servo motor. This can result in a savings of over 30 grams. Electronic switches are available, from R/C suppliers, that plug into the RC receiver and provide contact closure (don't get a RAM-35; it is designed for R/C control of several Amps, not several microamps). I made my own: see http://members.aol.com/hprinzler/index.htm for schematics.
Back to TopThere is no camera, that I am aware of, that meets all of these requirements. Some kind of compromise must be made. My current camera is a Pentax ZX-M (MZ-M in Europe) SLR which meets all of these requirements except weight (18 ounces).
Back to TopCompact cameras have a lot to recommend them for KAP. They are light, they have motor drives and are available in a range of price and quality ranges. Their main drawback is that they are too automatic. A manual camera gives several combinations of shutter speed and aperture for every lighting situation; most point and shoot cameras have automatic exposure features that only give one.
Modern Compact cameras have electronic shutters built into the lens. This configuration allows for a much quieter shutter, but has some limitations. In order to simplify construction, these electronic shutters function as both shutter and aperture diaphragm. When the shutter release button is pressed, the shutter will begin to open at some rate. The camera’s computer will stop this process after the shutter has opened to the desired aperture. The computer will wait for a length of time until the desired exposure is reached, and then it will begin to close the shutter, which will take some amount of time as well. For KAP, this mechanism has two undesirable side effects: First, for each light intensity (EV), detected by the light meter, there is exactly one combination of shutter speed and aperture. A table of these values is called the exposure program and is maintained by the camera’s computer; this table represents a modified form of aperture priority and cannot be changed by the user (see exposure program tables for Olympus Stylus Epic and Yashica T4). Second, because it takes a measurable time for the shutter open and to close, the minimum shutter time is highly dependent on the aperture. For example, The Stylus Epic advertises a top shutter speed of 1/1000 second, but this is true only at an aperture of f/11. It takes much longer (1/200 second) for the shutter to open to the maximum f/2.8 aperture. Bright sunlight corresponds to an EV of about 15 and would result in an exposure of about f/7 and 1/600 second (Olympus Stylus Epic using 100 ASA film). Unusually bright conditions would be necessary to bring the camera to its maximum shutter speed.
There are three ways for the photographer to shift this table:
Stroebel, Leslie, and John Crompton, and Ira Current, and Richard Zakia. Basic Photographic Materials and Processes. Focal Press, Boston: 1990
Williams, John B. Image Clarity : High-Resolution Photography. Butterworth-Heinemann: 1990
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