Tabular grain emulsions containing laminar halide strata

A photographic emulsion comprised of radiation sensitive silver iodobromide grains,

• at least 50 percent of the total projected area of said silver iodobromide grains being accounted for by tabular grains exhibiting a means tabularity of greater than 5, at least 10 percent of which are comprised of
• two opposed parallel major crystal faces,
• a host stratum having an iodide content of at least 4 mole percent, and
• laminar strata containing less than 2 mole percent iodide forming said opposed major crystal faces and separating said host stratum from said opposed major crystal faces,
• characterized in that each of said laminar strata is comprised of
• a surface layer forming one of said major crystal faces and having a thickness in the range of from 20 to 350 .ANG. and which is not doped with a transition metal coordination complex, and
• a subsurface layer located immediately beneath and in contact with said surface layer containing a hexacoordination complex of a Group VIII period 4 or 5 metal and at least three cyanide ligands.