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ENLARGED NEGATIVES: THEORY & PRACTICE

If the darkroom is light-tight enough to load fast film without fogging it we can turn our attention to the enlarger. Every enlarger I have seen leaks enough light to fog film and we need to plug up these leaks before exposing any film. Put a lens cap on the enlarging lens, put a negative carrier in , turn out the room lights and wait a few minutes for your eyes to adjust, and turn on the enlarger. All that light hitting the walls, ceiling, and you is non image-forming, fogging light and must be eliminated. Velcro and strips of black cloth are very helpful here. Now that we have the enlarger plugged up, put a piece of white paper in the easel, take off the lens cap, open the lens, darken the room and turn on the enlarger. The light illuminating the walls, ceiling and you is now caused by bounce from the easel and will fall back onto the film and fog it. Paint the walls and ceiling around the enlarger a very dark grey (black seems too depressing) and wear a black shirt when making negs. Some of the films you might use have no antihalation backing on them, so paint your easel flat black. Now we should have a darkroom.

There are some other situations in our lab that need our attention to make the transition from silver printing to negative making. Consistency is essential if we want to reproduce results, or make changes to contrast and density in a predictable manner. A voltage stabilizer to control the current going to the timer and enlarger is well worth the investment. Even if your lab is on a single circuit from the fuse box so that the refrigerator in the next room kicking on during an exposure doesn't affect the light output, there is enough normal line fluctuation from the electric company to noticeably change exposures. Electronic timers are much more consistent than their mechanical counterparts so their use is highly recommended. Sometimes it is desirable to make changes in exposure of fractions of a second, and this is not possible with a mechanical timer. A light integrator like the Metrolux, which controls exposure by measuring the total amount of light falling on the print represents the utmost in consistency.

While on the subject of the enlarger, let's turn our attention to the lens. The films we will be using are much faster than enlarging paper, so exposure times are naturally shorter, and the light intensity will have to be reduced. Simply stopping down the lens to 22 or smaller is not the answer. High quality enlarging lenses are sharper at wider apertures due to the effects of diffraction. You can check this by putting a negative in the enlarger and examining the grain with a high quality grain magnifier (focusing aid). Start with the lens wide open and notice how crisp the edges of the grain appear. Slowly stop down the lens and watch what happens to the crispness of the grain - on or about f/11 you should begin to notice a loss of sharpness, which tells us not to stop down any more if maximum sharpness is desired. If you want to cut down the amount of light beyond this use a neutral density filter.