With the Ronchi test a technician controls the manufacturing process using the following procedure: first, a Ronchigram is simulated which is scale-printed and placed on the surface as a mask and is usually printed with a low spatial resolution. This simulated Ronchigram is compared visually with the experimental pattern observed. This way of comparison leads to systematic errors in the evaluation of the surface, because it depends largely on the experience of the technician. Therefore, the main objectives of this work are to increase the spatial resolution and eliminate the dependence on the technician’s experience. Therefore, we compare the simulated Ronchigrams obtained by lateral shear interferometry, whose profiles are cosine, with Ronchigrams obtained experimentally. We present the simulation algorithm for the Ronchigrams of spherical and aspherical surfaces based on the expressions of a lateral shear interferometer. We show the results, of the comparison between simulated Ronchigrams (ray tracing and lateral shear interferometry) and experimental Ronchigrams. ©2013 The Japan Society of Applied Physics.