DIRECT POSITIVE SILVER HALIDE PHOTOGRAPHIC EMULSION

Direct positive silver halide photographic emulsion contains a combination of a cyanine dye sensitiser of formula I and a compd. of formula II: (where Z and Z1 are each atoms required for heterocyclic rings; R and R1 are each alkyl, or aryl; L1, L2 and L3 are each opt. substd. methine in which two of the substituents can be united to form a group of formula III: R6 is H or CH3; R7 is H, alkyl, aralkyl, phenyl or furyl; p and q are each 1 or 2; n is 1, 2 or 3; m is 1 or 2; X is an anion; Y is =CH- or =N-; R2, R3, R4 and R5 are each H, OH, alkoxy, aryloxy, halogen, alkylthio, arylthio, amino, aryl, mercapto, alkylamino, heterocyclylamino, or a heterocyclic group; A is a defined opt. satd. opt. aliphatic-contg. aromatic gp. opt. contg. HSO3 substituents, and when it does not contain any HSO3 gps., then at least one of R2-5 includes a sulphonate gp. Cpds. II decrease the tendency to reinversion and the minimum density of the emulsions.