Photographic silver halide emulsions

A silver halide photographic emulsion spectrally sensitized with a sensitizing combination of at least one sensitizing dye represented by General formula (I), at least one sensitizing dye represented by General formula (II), and at least one sensitizing dye represented by General formula (III):

• ##STR14## wherein Z.sup.1 and Z.sup.2 each is the atoms necessary to form a benzothiazole nucleus or a benzoselenazole nucleus, R.sup.1 and R.sup.2 each is an alkyl group or a substituted alkyl group wherein the substituted alkyl group is a substituted alkyl group having a sulfo group, a carboxy group, a hydroxy group, an allyl group or a benzyl group, and wherein at least one of R.sup.1 and R.sup.2 is a substituted alkyl group having a sulfo group, R.sup.3 is an alkyl group, X.sub.1 is an acid anion and m is 1 or 2, and when the dye forms an intermolecular salt (betaine like structure), m is 1;
• ##STR15## wherein Z.sup.3 is a sulfur atom or a selenium atom, Z.sup.4 is the atoms necessary to form a benzothiazole nucleus, a benzoselenazole nucleus, a naphtho[1,2-d]thiazole nucleus or a naphtho[1,2-d]selenazole nucleus, R.sup.4 and R.sup.5 each is an alkyl group or a substituted alkyl group as defined for R.sup.1 and R.sup.2, wherein at least one of R.sup.4 and R.sup.5 is a substituted alkyl group having a sulfo group, R.sup.6 is an alkyl group, an aryl group, a furyl group or a thienyl group, X.sup.2 is an acid anion and n is 1 or 2, and n is 1 when the dye forms an intermolecular salt (betaine like structure);
• ##STR16## wherein Z.sup.5 is the atomic group necessary to complete a naphthothiazole nucleus, Z.sup.6 is the atomic group necessary to complete a benzimidazole nucleus, R.sup.7 and R.sup.8 each is an alkyl group or a substituted alkyl group as defined for R.sup.1 and R.sup.2 where at least one of R.sup.7 and R.sup.8 is a carboxyalkyl group or a substituted alkyl group having a sulfo group, X.sub.3 is an acid anion, and p is 1 or 2, and p is 1 when the dye forms an intermolecular salt.