Questar Corporation is a company based in New Hope, Pennsylvania, which manufactures precision optical devices for consumer, industrial, aerospace, and military markets. Questars have been associated with many well-known scientists and other personalities; for example, in 1959, Wernher Von Braun purchased a telescope manufactured by the company. In development since 1946, the Questar 3-1/2” has been the companys 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.