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In the last article I explained how developers work. Development has a great influence on the final negative image and inappropriate development can cause serious problems for us when we come to print the negative. One of the misconceptions about development is that it increases the density of the negative, this leads to people giving their films extra development "just to make sure" that they get an image. Development controls the contrast of the negative, exposure controls the density. What "just to make sure" gives is a contrasty negative, with dense highlights and increased grain. This is due to the way the process of exposure and development link together. The more light each halide crystal in the film has received, the more development centres there are, so the faster it will develop. Heavily exposed highlight areas develop at a faster rate than lightly exposed shadows. The more development a film receives, the further the highlights move away from the shadows, so the more contrasty it becomes. Try it for yourself. Expose two films using the same film, subject and lighting. Do not use one of the "new technology" films, such as T-Max or Delta, which are more sensitive to exposure and development variations. Give one film "normal" exposure and the other twice "normal" exposure. Chop the normal "exposure" film up into three lengths and, using fresh developer, develop one length for the "normal" time, one for half that and the last for twice the "normal" time. Fix, wash and dry the lengths. Mark them up so that you can identify them easily. You may be surprised that there is an image on the film that was "underdeveloped" so much. Now develop the twice "normal" exposure film in the same way. Print the negs and compare the prints. The print from the twice normal exposure/half normal development neg will tend to show the smoothest range of tones and the least grain. Whilst the one from the half exposure/twice normal development neg, the harshest. Another way of putting it would be the print from the pulled film looks smoother than the one from the pushed film.
This test, and I can't over emphasise the value of doing tests in improving the technical side of your photography, is slightly extreme. In practice, you may find that you get the best results with any particular film/developer combination using smaller increases and decreases. Most likely, by rating the film at half-speed and giving a third less development than "normal". Regardless of whether you prefer smoother or harsher tones, the main lesson to be learnt from this test has nothing to do with exposure or development and everything to do with looking at your prints and deciding whether the techniques you are using to produce them matches your own style and intentions.
© Barry Leighton FRPS
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