| 摘要 |
1,195,838. Processing photographic silver halide materials. GEVAERT-AGFA N. V. Oct.3, 1967 [Oct.24, 1966], No.47633/66. Heading G2C. Carbazic acid, bicarbamic acid, substituted carbazic acid and bicarbamic acids and watersoluble salts thereof are used as foggants in photographic silver halide reversal processes. They may be present in the developer used in the second development stage of a black-and-white or colour reversal process or in a processing solution with which the material is treated before the said second development, and may partially or completely replace the usual overall light exposure. Direct-positive images may be obtained by imagewise exposing an internal latent image emulsion and developing with an energetic surface developer in the presence of compounds liberating iodide or bromide ions e.g. KI, the developer containing one of the above foggants or the material being treated with a solution of one of the above foggants before the surface development. |
