The requirement 0 in analog photography: Practical consideration negative film plus paper

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A print, unlike a slide, is the result of a two-stage process, and this means that the curves of the negative and positive must complement each other to produce the desired characteristic. Under these conditions, the most sensible way to match films and papers is to develop the negative to a low gamma value (typically < 1), to have the advantage of the large exposure latitude this provides, and then to steepen this low contrast to the required value (typically > 1) in the copying process.

For this reason, color negative films have characteristic curves as shown in figure 32. Their gamma values are around 0.7, they can cope with an exposure range of a good 11 exposure stops and have maximum densities of 2.5. The fact that the curves for red, green and blue are shifted upwards parallel to each other indicates a color cast of the respective color with even density, which is filtered out when it is copied.

Color papers have characteristic curves as in figure 33. With them, we typically find gamma values of 1.8, maximum densities of 2.5 and an exposure range of 5.5 exposure levels.

Although reversal films inherently have a very steep gradation, slide direct papers have gamma values similar to papers for color negative films (Fuji Type 35 paper is 1.6). The reason is that these papers are not supposed to reproduce the contrast „correctly“ at all. In the case of copies from slides, it is more a matter of conveying the high color saturation that we value so much in slides. And this is only possible through correspondingly high contrast.

Unlike silver-based imaging media, whose response is entirely inherent, digital imaging systems have inherent contrast behavior of their own.

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