Emulsion mixture for color reversal (reflection viewing) material

A process for the preparation of a silver halide emulsion layer for reversal photographic materials comprised of at least two individual emulsions, by

• (a) precipitation of the silver halide in a protective colloid,
• (b) physical and chemical ripening including precipitating and ripening separate and individual emulsions under conditions providing particle size distributions of a narrow particle size distribution, and resulting in substantially identical particle sizes and identical size distribution
• (c) during said preparation process and prior to completion of ripening adding to only one emulsion at least one compound in a desensitizing amount and selected from the group consisting of rhodium, copper and lead compounds,
• thereby providing in said emulsion a differential in desensitizing
• and then mixing of the individual emulsions,
• applying the mixture in the photographic material to a support in a layer,
• in which material the individual emulsions are desensitized to differing extents by the addition of at least one desensitizing compound to said one emulsion, of said desensitizing compounds
• whereby the individual emulsions in the applied layer prior to exposure to light contain different desensitization values than the layer has when subjected to variations in development or developer a minimal displacement of contrast gradation curves at the region of relatively high intensity of exposure.