The method of complete digital photocameras calibration using one image of plane test object is explained. The method is based on comparison of a real image to the “ideal” image of the same object, received from the same point, the free from distortion and with the known elements of internal orientation. Mathematical reasons for a method and calculation of admissible mechanical errors in case of manufacture of the calibration device are given. As an example of implementation calibration method it is provided image processing of the digital monitor with the regular network of points displayed on. It is presented the corrected image for distorsion.