Mar. 2003
President's
Message
Photo FAQs
Photo FAQs
Eric Kissa
Q: I was very surprised by your answer to the question, “Should I start with slides or prints?” Category Class B is mainly for beginners who just want to take pictures and improve. This category requires only a camera to produce commercially processed pictures for competition.
A: You are right, commercial prints are a viable alternative to slides. Unfortunately, commercial prints are not the best medium for learning purposes. The problem is the lack of control a beginner has over several variables. If the color of the print is not right, a beginner may not know whether the exposure or the printing is at fault.
The processed film comes with small prints and some frames have to be selected for ordering large (8x10 or 8x12) prints. The quality of the small machine prints may not be adequate for a critical selection of the best frames or for a critical review of the exposure conditions. If a filter is used or the exposure is varied for creative purposes, a machine printer will automatically equalize the color and erase the effect.
The selected frames can be printed by a machine or by a custom process. The quality of machine prints is variable and custom printing is desirable, especially when cropping is needed. This increases the expense, however.
The cost of a roll of processed negative film including small prints and the cost of a roll of slide film are roughly comparable. The cost of large prints needed for competition makes the commercial print route more expensive. The convenience is another factor to consider. A slide (transparency) film requires one trip to the photo lab or to a mailbox, a negative film requires two trips to a processing facility before the prints are in hand for the competition.
If the camera is used primarily to make prints for a personal picture collection and equipment for making prints is not available, then commercial printing is the only way to compete. Photography can be learned with commercial prints. However, a slide (transparency) film is a more demanding medium for learning how to get correct exposures, control color rendition, compose in the viewfinder, fill the frame, and experiment with creative effects. If the images are not as good as expected, there is nobody else to blame.
Q: A lot of diffusion filters are on the market. How do they differ?
A: The diffusion filters reduce small skin imperfections, soften wrinkles and create a dreamy look of portraits and landscapes. These filters diffract some of the light rays and do not affect other rays passing through the filter. The unaffected rays create a sharp image while the diffracted rays produce an overlaying soft image. The overall effect depends on the type of the filter. Some diffusers affect both the contrast and sharpness (resolution), some reduce mainly contrast and others mainly sharpness (resolution). The softening effect of some diffusion filters increases with the focal length and the aperture of the lens. A slight overexposure increases softening and an underexposure decreases softening.
The diffusion filters are sold with a confusing variety of names but the softening effect of all diffusion filters is caused by (a) irregularly distributed particles on the filter surface (b) concentric rings on the surface, or (c) a net in the filter.
Particles on the filter surface act like little lenses and dissipate the light striking them. As a result, the overall contrast as well as the resolution of the image is reduced. The softening effect depends on the shape, size and the distribution of particles on the filter surface. These “lenslet” filters are the most common (Zeiss Softars, Tiffen Soft/FX, Hoya Diffuser). The Zeiss Softars are the favorites of professional portrait photographers in spite of the very high price. The particles on the filter surface may be colored (Tiffen Black and Gold Diffusion/FX) or the particles are on a colored filter (Tiffen Warm Soft/FX).
Diffusion filters with concentric rings etched on the filter surface (Hoya Duto) keep the center of the image is usually sharp while the contrast is reduced and the highlights are softened. The etched lines may be symmetrical or asymmetrical. Tiffen’s Pro Mist/FX filters have a textured glass surface.
The effect of net in the diffusion filters increases with the decreasing size of the mesh. The finer the mesh of the net, the stronger is the effect. Net filters come in three colors: white, flesh color, and black.
The diffusion filters come in three or five grades. A larger number indicates a stronger effect.
Center clear diffusion filters have a clear center spot surrounded by a diffusing area. The size of the clear spot on film depends on the focal length of the lens. A longer focal length produces a larger clear area. Focal lengths shorter than 50mm are not recommended.
Some diffusion filters may interfere with the auto focus operation of the camera.
To choose a diffusion filter is not easy. The diffusion effects of different filter types are not expressed in simple quantitative terms and the large variety of filters excludes comparative testing. Once the decision is made on which type to buy, then the grade of the filter requires another decision. Usually a set of three or five grades is purchased.
Do-it-yourself diffusion filters are made by smearing petroleum jelly on a filter or by spraying a lacquer on a glass plate.
Q: Which mail order stores are reliable?
A: I have ordered from B&H and Adorama for many years without any problems. New York has several other reliable mail-order stores, as well as some unreliable ones. For specialty items Porter, in Iowa, is very satisfactory. However, we should not forget our local camera stores, we need them. In a local camera store we can buy an item we can see and get something we need immediately instead of having to wait for a few days. Beginners, especially, are better off buying locally. A mail ordered item may not be what they really wanted. Some attractively priced cameras and lenses are “gray market” imports sold without a warranty. Do not forget the shipping charges, and, if the equipment is faulty, you have to pay return postage and insurance.
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Send questions concerning photographic
equipment (cameras, lenses, accessories, filters), photographic techniques
(other than digital), and film, as well as information on international
photographic exhibitions, to: ekissa @aol.com.