|Headquarters||New Hope, Pennsylvania, USA|
|Donald J. Bandurick, President and CEO|
|Products||Optical / mechanical devices|
Questar Corporation is a company based in New Hope, Pennsylvania, which manufactures precision optical devices for consumer, industrial, aerospace, and military markets.
The Questar 3-1/2” Maksutov Cassegrain
In development since 1946, the Questar 3-1/2” has been the company's most notable product. Braymer’s basic concept for the telescope was one of portability, compactness, and ease of use. He used a "Catadioptric" Maksutov design, named after its inventor Dmitry Maksutov, for the optical tube assembly. Braymer used a modified Cassegrain design that added an aluminized spot to the Maksutov corrector plate, creating a compact folded light path (this design is sometimes called a "Spot- Maksutov). To avoid a conflict with a design patent held by John Gregory licensed to Perkin-Elmer, Braymer put the secondary spot on the outer (R1) surface of the corrector lens. In the mid-1960s the patent issue was settled, and Questar’s Maksutov-Cassegrains after that time use the Gregory design with the aluminized spot on the inside of the corrector (R2). The design was originally envisioned as a 5-inch (130 mm) telescope, but it was decided a telescope of that size would not fit the market they were aiming for, since it would be too heavy and expensive.
- Kennedy Space Center's Amateur Astronomers' "A TELESCOPE FROM HISTORY OWNED BY DR. WERNHER von BRAUN"
- TelescopeOptics.net, 10.2.3.3. Maksutov-Cassegrain telescope "Questar Maksutov-Cassegrain, a design very similar to Gregory's (in order to avoid patent infringement, Questars had - for about a decade - the aluminized spot placed at the front meniscus surface)"
- Paul Yates, THE QUESTAR, COSMOS - HEBDEN BRIDGE ASTRONOMY SOCIETY, page 7, September 2000
- Sky & Telescope Magazine - November 2002, S&T Test Report : The Questar 50th Anniversary Edition Telescope