His most well known contribution in the field of optics was made in 1941, when he invented the Maksutov telescope which corrected for spherical aberration by placing a corrector lens in front of the primary mirror.
His most well known contribution in the field of optics was made in 1941, when he invented the Maksutov telescope. Like the Schmidt telescope, the Maksutov corrects for spherical aberration by placing a corrector lens in front of the primary mirror.