The software which allows calculating signal to noise ratio amplification factor shading error visual quality modulation transfer function is developed. It appreciably decrease measurement's time and allows to lower risk of errors appearance. With the help of this software the distance between parallel sides hexahedron (about 700 microns) is received. Average grid linewidth is measured. Reduction ofbrightness by lines ofa grid is 10-20%. The dependence of a line width of "grid" from photocathode intensity is received.