Dmitri Maksutov's scientific legacy.
Dmitri D. Maksutov was born into a sailor's family in Odessa in 1896. From his earliest childhood he was quite interested in astronomy, and at about age 12 he made a reflecting telescope with a 180-millimeter (7-inch) mirror. Soon thereafter he completed a better, 210-mm reflector, attracting such attention with his celestial observations that he was elected to the Russian Astronomical Society at the remarkable age of 15!
Maksutov graduated in 1914 from the Military Engineering College. After several years of military service, and following the turmoil of the Russian Revolution, he returned to his optical work.
As a young scientist in the 1920s Maksutov explored the general properties of two-mirror optical systems and found a number of aplanatic combinations - those free of both spherical aberration and coma. Eventually he obtained a general solution for aplanatic systems. His main published articles in those years were "The Minimum and Maximum Magnification of a Telescope" (1925) and "A Single-Lens Ocular Without Chromatic Difference of Magnification" (1929). He also invented the reflecting microscope objective and the photo-gastrograph, a device for taking pictures of the stomach.
Then, as today, Leningrad (now St. Petersburg) was the center of Russian optical science. In 1930 Maksutov began to work at the State Optical Institute there, perfecting test procedures and producing high-quality two-mirror telescopes. In his 1932 book, Aberration-free Reflecting Surfaces and Systems and New Methods for Testing Them, he discussed the pros and cons of aplanatic systems. He also described for the first time a null test for large telescope mirrors using an auxiliary spherical mirror of significantly smaller size. (This test was first applied in the 1950s to the primary mirror of the Crimean Astrophysical Observatory 2.6-meter reflector.)
In 1941, after many years of hard work, Maksutov invented his famous class of telescopes having meniscus correctors. Wishing to create inexpensive instruments of high image quality, he decided to use spherical optics throughout. He showed how the large negative spherical aberration of the primary mirror could be compensated by the positive aberration of an achromatic meniscus lens. He also discovered that such a system, in addition to being aplanatic, is almost completely free of astigmatism.
Amid the confusion of World War II, in 1941 Albert Bouwers in the Netherlands and K. Penning in Germany independently filed for patents on meniscus systems. But today Maksutov is almost solely credited with the approach. In his classic monograph, "New Catadioptric Meniscus Systems" (Journal of the Optical Society of America, May 1944, pages 270-284), he explained how any reflecting telescope can benefit from meniscus principles. He went on to describe meniscus versions of Newtonian, Cassegrain, Gregorian, Herschelian, Mersenne, Schmidt, and Ross-type reflectors.
Quickly the concept spread around the world. Many ultrafast and ultra-wide-angle cameras, such as the Baker Super-Schmidt, employ meniscus ideas. The Questar, Celestron C90, and newly announced Meade 7-inch LX50 are examples of Maksutov-Cassegrain designs. So are the telephoto mirror-lenses made by Askania, Vivitar, Wollensak, Zoomar, Zeiss, and other companies. Amateur telescope makers also became caught up in the excitement. Allan Mackintosh of Indiana University formed the Maksutov Club in 1956, editing its popular Circulars for more than two decades.
Back in Russia, Maksutov became involved with larger and larger telescopes. One was the 700-mm meniscus instrument for planetary work installed in 1956 at the Abastumani Observatory in Soviet Georgia. Another 700-mm telescope, with an unusual double-meniscus corrector, was built in Russia and installed at Santiago, Chile, in 1966. Maksutov also played a key role in the design of the 6-meter reflector.
Maksutov combined theoretical insight with a thorough mastery of how to fabricate all kinds of optical surfaces, including prisms and flats. He personally made the optics for the 381-mm Schmidt telescope of the Engelhardt Astronomical Observatory in Kazan. Ribbed metallic mirrors also intrigued him, and he once figured a 720-mm metal paraboloid.
The long list of Maksutov's scientific works includes a few papers on medicine, wind tunnels, and the composition of optical glass. A member of the U.S.S.R. Academy of Sciences until his death in 1964, he possessed great erudition and yet remained very approachable and modest. One of his most important books, Manufacture and Testing of Astronomical Optics (1948), is only now being translated into English; it is to be published by Willmann-Bell.
LUDMILA A. GERASIMOVA Institute of Fine Mechanics and Optics St. Petersburg 197101, Russia
A research associate who received her Ph.D. in 1992, Gerasimova specializes in techniques for measuring refractive indexes.