Multicolor photographic elements exhibiting an enhanced speed- granularity relationship

摘要

Multicolor photographic elements are disclosed containing at least three dye image forming layer units. An enhancement of the speed- granularity relationship of a dye image is obtained when the corresponding dye image forming layer unit contains at least three superimposed emulsion layers. The two emulsion layers farther from the support contain silver bromoiodide emulsions, with the emulsion layer nearest the support containing a silver bromide or bromoiodide emulsion of up to 60 percent the iodide as a proportion of silver of the next overlying of the emulsion layers. The three emulsion layers each differ in speed from the next adjacent of the emulsion layers, with the fastest of the emulsion layers being located nearest the source of exposing radiation and being at least one half stop faster than the next adjacent layer and the slowest of the emulsion layers being located farthest from the source of exposing radiation and being at least one stop slower than the next adjacent layer. The three emulsions layers are each tabular grain emulsion layers with tabularities of greater than 25. At least the two emulsion layers nearest the source of exposing radiation tabular grains that contain a speed enhancing locally increased iodide content.