An analysis of a shear interferometer based on double-exposure recording of hologram of the image of a mat screen when the image is focused with a Kepler telescope is presented. It is shown both theoretically and experimentally that spatial filtration in the hologram plane enables one to control the field of the telescope. The spatial filtering in the Fourier plane makes it possible to record the interference pattern characterizing the phase distortions introduced in the wave illuminating the mat screen by the aberrations of the illuminating optical system.