Abstract

The observations of Biltz that, under certain conditions, reciprocity failure occurs at low temperatures (e.g., −196°C) have been confirmed. The failure is only of the high-intensity type and is restricted to emulsion-developer combinations of relatively low sensitivity, in particular, to surface image development of nonchemically-sensitized emulsions. At −196°C, the effect is exhibited most readily by silver bromoiodide emulsions.

The effect represents an intensity-dependent recombination of electrons and positive holes released m a grain at low temperatures, thus modifying the number of electrons available for latent-image formation on warming up. The mechanism proposed for superlinear fluorescence adequately accounts for all observations and the connection between low-temperature reciprocity failure and fluorescence of the silver halides is established.

The description of the dependence of sensitivity on temperature is revised. It is now apparent that, with certain emulsion-developer combinations, the speed loss from the normal temperature optimum to a low temperature may contain a factor additional to the absorption and ordinary high-intensity-failure speed losses.

© 1957 Optical Society of America

Dependence of the Sensitivity of Unsensitized Photographic Emulsions upon Temperature*

Martin Biltz
J. Opt. Soc. Am. 39(12) 994-1008 (1949)

Photographic Sensitivity as a Function of Exposure Time and Temperature*

M. Biltz
J. Opt. Soc. Am. 42(12) 898-903 (1952)

An Experimental Study of Latent-Image Formation by Means of Interrupted and Herschel Exposures at Low TemperatureMeasurements of Reciprocity Law Failure at Low Temperature*

J. H. Webb and C. H. Evans
J. Opt. Soc. Am. 28(7) 249-263 (1938)

The Effect of Temperature upon the Spectral Sensitivity of Photographic Emulsions*

C. H. Evans
J. Opt. Soc. Am. 32(4) 214-218 (1942)

The Effect of Temperature upon Reciprocity Law Failure in Photographic Exposure*

J. H. Webb
J. Opt. Soc. Am. 25(1) 4-23 (1935)