A method of calibrating the spatial distribution of photosensitivity of matrix photodetectors without the use of reference optical radiation intensity distributions has been developed and experimentally verified. A scheme of the experimental setup implementing the method, an experimental procedure, and two modifications of the algorithm that reconstructs spatial distributions of photosensitivity using the measurement results have been developed. Experiments on calibrating the spatial distributions of photosensitivity of CCD matrices have been performed. It is shown that, using the presented method, calibration of the spatial distribution of photosensitivity of matrix photodetectors permits one to almost eliminate systematic error when detecting spatial distributions of the optical radiation intensity.