Morphometric investigations of light or electron microscopic photographs can be both time consuming and tedious when statistical results are to be obtained. Therefore, an opto-electrical morphometer has been developed to facilitate such investigations. The photograph is placed in between a light source and a grid, and the shape of the object in question is outlined with an electronic pencil. The impulses so produced can be converted into counts which may than be fed into a pocket-sized calculator or micro-computer for further analyses.