The possibility of digital photographing method application to register the humane erythrocytes agglutination in vitro, intensified by ultrasonic standing wave, is demonstrated. The analysis of digital photographs brightness distribution along the depth of the cuvette filled by "blood - agglutinating serum" solution gave an opportunity to choose the zone for mathematical processing in which the resolving power of the method has maximum. For the zone chosen the analysis of the probe preparation features influence upon the magnitude of resolving power to register erythrocytes agglutination reaction was realized. The results may be used to develop optical method and device supplied by ultrasonic intensification of erythrocytes agglutination for the aims of humane blood group typing.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.