An instrument (densitometer) for the measurement of high photographic densities

✍ Scribed by Loyd A. Jones

• Publisher: Elsevier Science
• Year: 1923
• Tongue: English
• Weight: 140 KB
• Volume: 195
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(23)90146-8

✦ Synopsis

existence of statistical variation of sensitivity among silver halide grains is discussed. For photolysis in a homogeneous system, a mathematical expression is developed relative to the density-exposure function and has the formula D' = -In [ e-L',n + (I _ 'z-D,+ &+"J]+ 1'1 le relation of statistical variation of inertia to the density-exposure function will correspond with the inertiavariation function.

Conditions permitting this correspondence are noted.

If the size-frequency corresponds with the sensitivefrequency then the curve of " reciprocity size-frequency " gives the inertia-variation curve; integration of this, the clensityexposure function.

For the most general case where dD/D,,, -D = k'dE and k = f(i) or a function of inertia, the integration gives D = D, (I -P ) 1% Th ere /L .= D,,,/k'( I -E-~'~) .E is the exposure and D,, the maximum density.