Fuji Photo Film Company, Limited

Kazumi Watase

Hiroyuki Hirai

Isao Tsuyuki

Sachio Matsushita

Yoshio Inagaki

Shigeo Hirano

Eiichi Okutsu

Eiich Okutsu

A process for hard tone development of a silver halide photographic light-sensitive material is described, comprising developing an imagewise exposed negative type silver halide photographic light-sensitive material in the presence of hydrazine, usig a developing solution comprising (1) a developing agent, (2) 0.25 mol/l or more of sulfite and (3) a compound represented by the general formula (I) and having a pH value of 10.5 to 12.3: ##STR1## wherein R.sub.1 and R.sub.2 represent each an alkyl group of R.sub.1 and R.sub.2 may form a ring by linking each other, R.sub.3 represents an alkyl group, an aryl group or a heterocyclic group, and R.sub.1, R.sub.2 and R.sub.3 may have substituents, A represents an alkylene group which may be substituted, and X represents --CONH--, --OCONH--, --NHCONH--, --NHCOO--, --COO--, --OCO--, --CO--, --NHCO--, --SO.sub.2 NH--, --NHSO.sub.2 --, --SO.sub.2 --or --O--.

Process for hard tone development of silver halide photographic

A method for developing an exposed negative silver halide photographic light-sensitive material is described, in the presence of a hydrazind derivative, comprising treating the material with a developer containing at least components (a) a developing agent, (b) not less than 0.25 mol/liter of a sulfite, and (c) not less than 0.1 mol/liter of a compound having an acid dissociation constant of from 1.times.10.sup.-11 to 3.times.10.sup.-13, and having a pH value of from 10.5 to 12.3.

Developing method

The concentration of halogen ions in a photographic developer is controlled at an almost constant value by determining the concentration of halogen ions in the developer by detecting the change in electric potential caused by the addition of silver ions to the solution, and controlling the electrical current supplied to a halogen ion removing means, such as an electrodialysis or an electrolysis unit having an anion exchange membrane, based on the result of the determination of halogen ions. By this method the amount of complementary developer added to a fatigued developer solution can be greatly reduced.

Method and apparatus for controlling halogen ion concentration in a

Method for controlling halogen ion concentration in a photographic

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Minami-ashigara, Japan

Kazumi Watase