Chloride-rich (100) tab grain emulsions of specified average aspect ratio and crystal thickness and particle size distribution ranges have high spectral sensitivity and good storage stability

摘要

A cubic-form tabular AgCl or AgClBrI emulsion of Cl content =90 mol.% and I content 0.01-5 mol.% is such that =80% of the crystals (based on the projected surfaces of all of the crystals) have an average aspect ratio of =8, a crystal thickness distribution range of maximum 15% and a particle size distribution range of maximum 25%. Also included is an INDEPENDENT CLAIM for production of the emulsion involving seeded precipitation followed by crystal growth such that =50% of the total Ag is transformed and the crystal edge length (r) is 0.1-10mu , with the supersaturation in the reaction medium being given by the relationship 'S is less than -0.064 lg(r/r*) + 1.43' where r* = 1nm.