SUB-IMAGE FORMATION BY OXIDATION OF LATENT IMAGE

We demonstrate that various combinations of sensitization, exposure ti me, and rate of oxidation produce sub-image centres if latent image ce ntres in silver bromide grains Rue carefully oxidized. First we confir m that sub-image is formed by relatively slow oxidation of latent imag e in sulphur-plus-gold-sensitized grains exposed for 10(-4) s. An incr ease in the rate of oxidation leads to the same result. Relatively slo w oxidation of latent image in unsensitized grains exposed for 10(-4) s and in sulphur-sensitized grains exposed at 10 s also produces sub-i mage.