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Copy Slides For The Artist |
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A good quality copy slide should be an excellent
representation of the original work. It is especially
important today for the artist to be capable of making
excellent copy slides. In many cases employment, exhibitions,
graduate school admission and grant applications are judged
from copy slides.
Equipment and Supplies for Copying Any good 35mm camera can be used for copy work. A single lens reflex camera with through the lens metering is preferable and makes copy work much simpler. However, a range finder can be used with special measuring devices for copy work. Many cameras do not focus closer than three feet so a close-up lens may be necessary for copying small subjects. A simple close- up lens is inexpensive and screws to the front of the camera's normal 50mm lens to allow it to focus closer and give greater magnification. There are other accessories that can be used to photograph small subjects using a basic 50mm lens if your camera will take interchangeable lens. Extension tubes and bellows attachments can be necessary for extreme close-ups and high magnification, but for general copy work a simple close-up lens is adequate, simple to use, and less costly. A normal 50-55mm Macro Lens on a 35mm single lens reflex camera is an extremely versatile system for both copy and general photography. This lens barrel is designed to extend to such a length that photgraphs can be taken from infinity to minimum distance of about 23.2 cm without additional attachments. You can work from infinity to 1:2 magnification. Many of these lenses come with an extension tube that allows 1:1 magnification. Camera Support and Light Fixtures A stable, rigid camera support is needed for any type of copy work. A good quality tripod is excellent for general copying. Heavy-duty copy stands are convenient if you regularly do a great deal of flat copies of small to medium size. You will need a flexible cable release for tripping you camera shutter. A light meter in the camera or a hand meter is essential for accurate exposures. Kodak Neutral Test Cards, 18% Gray are useful for taking an exposure reading. The simplest system of artificial light is a pair of Smith Victor 12 in reflectors and two light stands. These can be used to light most subjects. For very large subjects four lights are sometimes needed. These reflectors will accept 250 and 500-watt photographic lamps. Lighting and Film For general copy work you need two light sources of equal intensity and age with stands and reflectors for each. When using color film the color temperature of the light source must be balanced for the film you use. Photographic bulbs come in two color temperatures, 3200K and 3400K and in 250 and 500-watt sizes. They come in regular bulbs and in reflector-type bulbs. Tungsten 3200K bulbs have a longer life and should be used for black and white copy work. For copy work, use a film that has a fine grain or structure and excellent resolution. Films of a slower ASA generally have these characteristics, and since you are using a tripod Kodachrome films are by fare the sharpest, high-resolution material available. They are also the most archival and fade resistant. Because the must be processed by Kodak, it takes more time to have them processed and returned. Ektachrome 50 Professional is an excellent copy film which you can process yourself or have processed at a local lab with same day service. These films are recommended for general copy work use. Black and white slides are cheaper to make when color is not necessary they give excellent results. Using Kodak Panatomic X and a higher ASA rating, this film can be developed in a Kodak Direct Positive Film Developing Outfit to give fine quality slides. If you want these slides you will have to process the film yourself since labs do not do this process. Suggested Film for Copy Work
Camera and Lamp Set-up for Copying For basic flat copy set-up the camera should be set up so that the lens axis is at the center and Parallel to the surface to be copied.  If
the camera is tilted the subject will be distorted. The
subject can be placed on a wall or flat surface. The two photo
lights should be evenly spaced at a 45 degree angle to the
lens axis, and the camera back must be parallel to the surface
copied. The distance of the lights from the subject will vary
with the subject size, but do not place them closer than 30
inches since they five off a lot of heat. Find the center of
the area to be copied and us a string or tape measure to space
your lights slightly off center and overlapping so that there
is no hot spot in the center of your image. The lights should
be far enough away from the subject to cover it evenly. Large
subjects will need two lights or more on each side for even
illumination. To check for evenness of the light place a
pencil in the center of the area to be copied. If the two
shadows it casts are equal, the lighting is balanced. If one
shadow is much darker, the lights are not of the same
intensity. To adjust for this, move the brighter light farther
away along it's own axis until the shadows are equal.
When copying on a white wall or surface put black behind the subject so that light is not reflected on the lens causing a flare. Flare causes a loss of sharpness and contrast. Be careful not shine you light directly at the camera lens since this will also cause a flare. A set of barndoors on your lights can be very useful or they can be shadowed with black cards. Exposure Calculation A built-in, through the lens meter is very accurate for exposure calculation. All meters read 18% gray regardless of the tone of the subject. Put an 18% gray card in the position of the subject and take your reading from it rather than the subject itself. For general copy work this will consistently give you excellent quality copies. It is suggested that you bracket your exposures on the test roll. Expose one frame as the meter indicates and for color slides make one a ½ stop less and a ½ stop more. For black and white you can bracket by a full stop up and down. With experience, this type of bracket is unnecessary. For copy work a lens at f/8 or f/11 will give optimum performance of highest resolution and sharpness. For flat copy you do not need much depth of field so it is not necessary to use a small f stop. Textured Surfaces and Dimensional Objects With highly textured surfaces in a standard copy set-up the shadows can become too distinct. To eliminate this problem you can use diffusers over your lights. Smith Victor makes clip-on diffusers or you could use a tracing paper flat to soften the light and eliminate harsh shadows. With dimensional surfaces you may not want even light from both sides. It might be more natural looking to have one light dominate as your main light source to avoid double shadows. With three-dimensional subject in artificial light it is better to use only one main light source. Remember that there is only on sun and shadows are important to five feeling of shape and form. Equal light from both sides is generally flat. To put some light back into the shadows use a white card of a foil reflector, which will five fill and shadow detail. When shooting a three dimensional subject in color, use a diffused light source, since you pick up contrast in the slide. Keep your background simple so that the object copied dominates. You can use background paper, illustration or poster board, fabric, or a plain wall as a background. Highly Reflective Surfaces and Goboing the Camera With very shiny or glossy surfaces a more diffused light will cut down on surface reflections. A Polarizing Filter over you camera lens removes or reduces reflections from non-metallic surfaces. This filter has a 2 stop factor and is simply rotated until optimum effect is obtained. Under extreme situations polarizing filters can be placed over the lights as well as the camera lens. When using a piece of glass to hold down flat copy like a book or when copying something framed under glass, use a black card with a hole in front of the camera. This is called Gobo and is used to keep the reflection of the camera and anything else from reflecting in the glass. This card should be black on both sides. Additional Copy Information If the color of the copy must be very close to the original, you should first shoot a test roll. View these transparencies on a balanced light box with Color Correction Filters held over them. Re-photograph the originals using the filter that makes the color look most correct over the camera lens. Kodak Color Compensating Filters come in 2, 3, and 4 inch gelatin squares and can be used in a filter holder or taped over the lens. They come in both additive and subtractive primaries. Electronic flash is very useful for copy work on location, in museums or on gallery walls. Use color film that is daylight balanced. The main problem with flash is to keep the reflection of the flash in glass surfaces from ruining the copy. Use a bounce light which is more diffused and has less contrast and get your flash unit off the camera by using an extension cord to move the light source off the axis of the lens. For copying outdoors the simplest lighting is semi-overcast daylight. Bright sunlight may wash out the color and give too much contrast. Be aware of shadows and be sure that the light is even. Work when the color of light is neutral generally mid-day. Use a skylight filter to cut down on the blue reflected from the sky on the subject. If you slides are not commercially processed you will need slide mounts. Plastic mounts are convenient and available. If there is any extraneous background in the slide it can be masked out using slide masking tape. Label all you slides with basic information. A dot placed in the lower left hand corner of the base side of the slide mount makes it easy to position the slide correctly. Related Links: Kodak (manufacturer) Sylvania (manufacturer) General Electric (manufacturer) Standardized Slide Labeling (MP Reference Article) Transfix Laser Slide Labels (manufacturer) |
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