Cyanine dye J-aggregates, a principal material which absorbs visible light in photographic films, are expected to adsorb on every AgBr microcrystal in equal quantity to achieve uniform sensitivity to exposing light throughout the photographic material. However the population densities of the J-aggregates on AgBr particles grown in gelatin differed significantly as identified by the cathodoluminescence from the aggregates; some particles adsorb little dye while others adsorb more, i.e. a few particles adsorb most of the dye and the rest adsorb little. The reason for the wide spread of J-aggregate distribution is unknown. The shapes of AgBr microcrystals look alike in microscopic observations and do not explain why such a significant difference of adsorbed dye quantities occurs. The wide variations of adsorbed dye, quantities on AgBr particles must be a major factor with respect to the sensitization/desensitization effects or latent image formation of silver halides with photosensitizing dyes.