The quantic exposure law (density as function of exposure) for a uniform emulsion. Emulsions containing silver halide grains of different sizes. General formulae and their application to emulsions of exponential and gaussian or “ormal” size-frequency distribution of grains. Some relations valid for any size-frequency distribution
✍ Scribed by Ludwik Silberstein
- Publisher
- Elsevier Science
- Year
- 1951
- Tongue
- English
- Weight
- 999 KB
- Volume
- 251
- Category
- Article
- ISSN
- 0016-0032
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✦ Synopsis
In the proper field of the art of photography and its practical applications, it is not the number and size of the individual grains made developable by an exposure which are required, but the macroscopic, summary effect of the presence of such grains, the opacity of the film or plate over which the developable and, ultimately, the developed grains, embedded in gelatin, are spread; in fine, the cumulative effect of such grains' in blotting out some fraction of the incident radiation.
If I0 be the intensity of the light incident upon and penetrating into a film, s and I the intensity of the transmitted light, the transparency, or "transmission" of the film is defined as the ratio T = I:Io * In this product, a is actually the area of the developed grain which will, in general, differ considerably from the area of the undeveloped grain appearing in our variable y.