Direct positive dimethine cyanine dyes containing 1-aryl-2-heteroaryl indole nucleus
申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:EP0296873A2
公开(公告)日:1988-12-28
A fogged direct positive photographic silver halide emulsion containing a sensitizing amount of at least one cyanine dye defined above, e.g., cyanine dye containing a 1-phenylindole nucleus substituted in the 2-position with the 3-pyridyl group. The said cyanine dye is also covered. The dye useful in sensitizing the silver halide emulsion useful for fogged direct-positive films.