John F. Gregory
Encyclopedia
John F. Gregory was an American optical engineer
and a popularizer of amateur telescope making
. He is credited with the design of a version of the Maksutov telescope
called the "Gregory-Maksutov telescope".
in 1927. He earned bachelor's and master's degrees in engineering from the Case Institute of Technology (now Case Western Reserve University
). In the 1950s he began his career working for Perkin-Elmer Corporation in Norwalk, Connecticut
. In 1974 he became chief engineer for the University of Texas McDonald Observatory
. In 1978 he left the observatory and opened Gregory Optics, an optical and telescope equipment consulting, design, and fabricating firm.
magazine entitled "A Cassegrainian-Maksutov Telescope Design for the Amateur".
In it, Gregory showed how to construct a version of the Maksutov catadioptric telescope
in which all optical surfaces are spherical, and which has as secondary a small aluminized spot on the inner surface of the corrector lens. Not only was Gregory's design simpler than the classical Maksutov design; it also had the advantage of fixing the alignment of the secondary, making the telescope more robust, and eliminating the need for a secondary support that would otherwise cause diffraction spikes in the image. Most Maksutov telescopes manufactured today are of this type, which has come to be called either a "Gregory-Maksutov" or a "Spot-Maksutov".
Gregory's article included detailed optical specifications as well as shop techniques and testing algorithms. Many more articles were published by Gregory and others on his design in the "Gleanings for ATMs" column in Sky & Telescope, culminating in the 39-page pamphlet Gleanings Bulletin C.
Gregory went on to design a 22-inch f/3.7 Maksutov telescope for the Stamford Museum and Nature Center
in Connecticut; this telescope is still the largest Maksutov in the U.S. In 1980 he donated an 8.2-inch f/16 Maksutov-Cassegrain that he had constructed to his alma mater, Case Western Reserve; he named it the "Nassau Memorial Telescope" after his former teacher there, astronomer J. J. Nassau.
At the 2006 Riverside Telescope Makers Conference, Gregory delivered the Robert Fulton Goff Invitational Lecture on Optics and Optical Design, entitled "My 60 Years of Astro-Optics".
and the Riverside Telescope Makers Conference. He was also active in politics, serving in several political action groups that lobbied for tort reform.
was struck by a pickup truck around 8:20 am. He and Carolyn were flown to University Medical Center Brackenridge in Austin
. John died later that day from injuries sustained in the accident; Carolyn was critically injured and survived for three months before succumbing to her injuries. The alleged driver of the pickup truck was charged with criminally negligent homicide.
Optician
An optician is a person who is trained to fill prescriptions for eye correction in the field of medicine, also known as a dispensing optician or optician, dispensing...
and a popularizer of amateur telescope making
Amateur telescope making
Amateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional. Amateur telescope makers build their instruments for personal enjoyment of a technical challenge, as a way to obtain an inexpensive or personally customized telescope, or as a...
. He is credited with the design of a version of the Maksutov telescope
Maksutov telescope
The Maksutov is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical". The negative lens is usually full diameter and placed at the entrance pupil of the...
called the "Gregory-Maksutov telescope".
Career
John Gregory was born in Cleveland, OhioCleveland, Ohio
Cleveland is a city in the U.S. state of Ohio and is the county seat of Cuyahoga County, the most populous county in the state. The city is located in northeastern Ohio on the southern shore of Lake Erie, approximately west of the Pennsylvania border...
in 1927. He earned bachelor's and master's degrees in engineering from the Case Institute of Technology (now Case Western Reserve University
Case Western Reserve University
Case Western Reserve University is a private research university located in Cleveland, Ohio, USA...
). In the 1950s he began his career working for Perkin-Elmer Corporation in Norwalk, Connecticut
Norwalk, Connecticut
Norwalk is a city in Fairfield County, Connecticut, United States. According to the 2010 U.S. Census, the population of the city is 85,603, making Norwalk sixth in population in Connecticut, and third in Fairfield County...
. In 1974 he became chief engineer for the University of Texas McDonald Observatory
McDonald Observatory
The McDonald Observatory is an astronomical observatory located near the unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Fowlkes and Mount Locke in the Davis Mountains of West Texas...
. In 1978 he left the observatory and opened Gregory Optics, an optical and telescope equipment consulting, design, and fabricating firm.
The Gregory-Maksutov telescope
In 1957, Gregory published an article in Sky & TelescopeSky & Telescope
Sky & Telescope is a monthly American magazine covering all aspects of amateur astronomy, including the following:*current events in astronomy and space exploration;*events in the amateur astronomy community;...
magazine entitled "A Cassegrainian-Maksutov Telescope Design for the Amateur".
In it, Gregory showed how to construct a version of the Maksutov catadioptric telescope
Maksutov telescope
The Maksutov is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical". The negative lens is usually full diameter and placed at the entrance pupil of the...
in which all optical surfaces are spherical, and which has as secondary a small aluminized spot on the inner surface of the corrector lens. Not only was Gregory's design simpler than the classical Maksutov design; it also had the advantage of fixing the alignment of the secondary, making the telescope more robust, and eliminating the need for a secondary support that would otherwise cause diffraction spikes in the image. Most Maksutov telescopes manufactured today are of this type, which has come to be called either a "Gregory-Maksutov" or a "Spot-Maksutov".
Gregory's article included detailed optical specifications as well as shop techniques and testing algorithms. Many more articles were published by Gregory and others on his design in the "Gleanings for ATMs" column in Sky & Telescope, culminating in the 39-page pamphlet Gleanings Bulletin C.
Gregory went on to design a 22-inch f/3.7 Maksutov telescope for the Stamford Museum and Nature Center
Stamford Museum and Nature Center
The Stamford Museum and Nature Center, located in Stamford, Connecticut, is an art, history, nature and agricultural sciences museum. The property covers 118 acres beginning about 1/2 mile north of the Merritt Parkway and was originally a private estate.- Facilities :The museum property was the...
in Connecticut; this telescope is still the largest Maksutov in the U.S. In 1980 he donated an 8.2-inch f/16 Maksutov-Cassegrain that he had constructed to his alma mater, Case Western Reserve; he named it the "Nassau Memorial Telescope" after his former teacher there, astronomer J. J. Nassau.
At the 2006 Riverside Telescope Makers Conference, Gregory delivered the Robert Fulton Goff Invitational Lecture on Optics and Optical Design, entitled "My 60 Years of Astro-Optics".
Personal life
John Gregory had two sons, Rick and Randy, with his first wife Barbara, lost his second wife Marion to brain cancer, and was married in 1998 to Carolyn. He was an accomplished pianist, jewelry maker, and pilot. He was a frequent attendee at meetings of amateur astronomers, including StellafaneStellafane
Stellafane is the name of the clubhouse built by the Springfield Telescope Makers club of Springfield, Vermont in the early 1920s, and has since come to refer to the club's land and buildings on the summit of Breezy Hill...
and the Riverside Telescope Makers Conference. He was also active in politics, serving in several political action groups that lobbied for tort reform.
Death
John Gregory died on November 14, 2009 following an automobile accident. The car his wife Carolyn was driving in Lakeway, TexasLakeway, Texas
Lakeway is a city in Travis County, Texas, United States. The population was 11,391 at the 2010 census; up from 8,002 in 2000. The city is located near Lake Travis.-Geography:...
was struck by a pickup truck around 8:20 am. He and Carolyn were flown to University Medical Center Brackenridge in Austin
Austin, Texas
Austin is the capital city of the U.S. state of :Texas and the seat of Travis County. Located in Central Texas on the eastern edge of the American Southwest, it is the fourth-largest city in Texas and the 14th most populous city in the United States. It was the third-fastest-growing large city in...
. John died later that day from injuries sustained in the accident; Carolyn was critically injured and survived for three months before succumbing to her injuries. The alleged driver of the pickup truck was charged with criminally negligent homicide.