Silver halide photographic materials comprising silver bromide or bromoiodide emulsions having triangular tabular grains

摘要

A light-sensitive silver bromide or silver bromoiodide emulsion is provided, comprising silver bromide or silver bromoiodide tabular triangular grains, said tabular triangular grains having an average grain thickness of less than 0.3 mu m, an average crystal diameter of at least 0.6 mu m; an average aspect ratio of at least 2:1; a variation coefficient of less than 40 %, said grains accounting for a total projective area of at least 30 %; characterised in that the thickness ratio of triangular tabular grains to hexagonal tabular grains is from 1.3 to 0.7.