The principle that the degree of darkening of an ideal emulsion is constant for a given incident energy, i.e. for a given product of light intensity and exposure time.
Origin
Early 20th century; earliest use found in Scientific Abstracts.
Definition of reciprocity law in US English:
reciprocity law
noun
Photography
The principle that the degree of darkening of an ideal emulsion is constant for a given incident energy, i.e. for a given product of light intensity and exposure time.
Origin
Early 20th century; earliest use found in Scientific Abstracts.