Abstract: A quantitative characterization parameter in. optical development of free radical photography K_max is proposed and its significance and method of measurement are elucidated. Effects of the wavelength (used) on the optical development of Leuco crystal violet/CBr₄ film and the effects of the adhesive medium and temperature on the rate of optical development have been studied. The activation energy is estimated at about 10kcal/mole.
The induction period of optical development has also been interpreted. There are two different processes in optical development. In the induction period oxygen quenching of the excited dye molecules by the diffusion-control predominates while in the main period of the reaction energy transfer-control photochemical reaction predominates.