Abstract The production of areas of equal density in a photographic image by combining in a photographic material two silver halide emulsions in one or two layers, one of which emulsions is more soluble in photographic developer than the other emulsion but the more soluble emulsion is lower in speed than the less soluble emulsion and the less soluble emulsion is present in a much smaller proportion. After the photographic material is exposed it is developed in a bath having a silver halide developing compound and a silver halide solvent for the slower halide emulsion so that the faster less soluble emulsion is developed in the exposed area to yield a negative silver image and the slower silver halide emulsion is physically developed to yield a positive image and chemically developed to yield a negative image. The developed material is finally fixed.
up to 10 percent by weight based on the total weight of the emulsions consist of a light sensitive, faster silver halide emulsion containing a different silver halide which is less soluble in the developer bath, said more soluble light sensitive, slower silver halide emulsion having a sensitIvity to white light lower by the factor of at least 1.1 than the sensitivity of the less soluble light sensitive, faster silver halide emulsion, developing the exposed material in a aqueous developer bath including a silver halide developing compound and a silver halide solvent for the slower silver halide emulsion, whereby the slower silver halide emulsion is physically developed to yield a positive silver image and additionally chemically developed to yield a negative silver image and whereby the faster silver halide emulsion is developed in the exposed areas to yield only a negative silver image and finally fixing the developed material.
Claim 2
Dependent Claim
35 words
The process of claim 1, wherein the more sensitive emulsion is a silver chloride emulsion, the less sensitive emulsion is a silver bromide emulsion, and the aqueous developer bath is substantially free of bromide ions.
Claim 3
Dependent Claim
33 words
The process of claim 1, wherein the more soluble silver halide emulsion has a sensitivity to white light which is lower by the factor 1:1-20 than the sensitivity of the less soluble emulsion.
Claim 4
Dependent Claim
25 words
Process of claim 2, wherein the sensitivity ratios of the silver chloride emulsion to the silver bromide emulsion towards white light are 1:10 to 9:10.
Claim 5
Dependent Claim
14 words
Process of claim 1, wherein the more soluble silver halide emulsion contain development nuclei.
Claim 6
Dependent Claim
43 words
Process of claim 2, wherein the silver bromide emulsion is spectrally sensitized to light from the blue region of the spectrum and the silver chloride emulsion is, in addition, spectrally sensitized to light from the green and/or red region of the visible spectrum.