Questar Corporation

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Questar Corporation

Type	Private
Founded	1950
Headquarters	New Hope, Pennsylvania, USA
Key people	Donald J. Bandurick, President and CEO
Industry	Manufacturing
Products	Optical / mechanical devices
Website	www.questarcorporation.com

Questar Corporation is a company based in New Hope, Pennsylvania, which manufactures precision optical devices for consumer, industrial, aerospace, and military markets. Its telescopes produced for the consumer market sold under the name brand name "Questar" have been referred to as the "Rolls Royce" [1] of astronomical instruments.[2][3]

1 Origins and history
2 Products
3 The Questar 3.5” Maksutov Cassegrain
- 3.1 Questar 3.5” notes
4 Trivia
5 See also
6 External links

[edit] Origins and history

Questar was founded in 1950 by Lawrence E. Braymer (born 1901, died 1965). A commercial artist by trade, Braymer set up Questar to develop and market Maksutov telescopes and other optical devices for the consumer, industrial, and government customers.

After the death of Lawrence Braymer, his widow Peggy became the sole owner of the company. In 1976 Dr. Douglas M. Knight was hired as the new President by Mrs. Braymer. In 2001 Questar Corporation was acquired by Donald J. Bandurick, President and CEO of the National Engineering and Manufacturing Company.

[edit] Products

Questar's telescopes are widely used in consumer, military, police, security, and industrial applications. Some of the products sold by Questar include:

3.5” and 7” Maksutov Cassegrain astronomical/terrestrial telescopes for the consumer market.

Surveillance versions of their Maksutov Cassegrain models.

Long distance microscopes, an adaptation of their Maksutov Cassegrain telescopes modified to image subjects at close range, used in research and manufacturing process quality control.

Specially built Maksutov Cassegrains for use in test range imaging and radar calibration/boresighting.

[edit] The Questar 3.5” Maksutov Cassegrain

In development since 1946, the Questar 3.5” has been the company's most famous 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.

Braymer designed a built-in “Control Box” that allowed the user, looking through the main eyepiece, to switch between the main telescope and a coaxial finderscope via moving a diagonal out of the way with a flick of a knob. This also allowed a camera or other device to access the focus plane through a hole on the back of the Control Box. A knob for focus and another to switch in and out a magnification doubling barlow lens rounded out the controls. The cast aluminum double fork arm mount was designed with a built in clock drive and became equatorial by adding the collapsible legs included.

The Questar 3.5” entered commercial production in 1954 and almost immediately this “observatory-in-a-box“ was considered the "Rolls-Royce" of telescopes. Ads for the model have run in many astronomy, science, photography, and nature related magazines such as National Geographic. They have focused on the telescope's mechanical and optical excellence, educational value for children, ease of use, and adaptations as a spotting scope and telephoto lens. Since it’s a complicated hand crafted instrument with a relatively small production run it has always come with an extremely high price tag. The design has been almost static since its first production with very little ability to use or even accept modern accessories. This has led the instrument to be to criticized as being a "status symbol" that is too small, too expensive, and just plain too outdated for serious astronomical use. Even so, it has gained a prestigious reputation and has become a favorite of those who can afford them.

[edit] Questar 3.5” notes

This model was originally envisioned as a 5” 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.

A Questar Standard 3-1/2 instrument resides in the collection of the Smithsonian Institution in Washington, D.C.; it is "cut-away" to reveal the various innovations unique to the Questar.

Questar does not produce their own optics. The earliest Questars used optics produced in part by Cave Optical, but for most of their history the optics were produced by [4]Cumberland Optical.

Questar optics are hand-aspherized to reduce higher-order abberations, in order to achieve a mininum 1/8th wavelength accuracy.

Versions of the Questar 3.5” were used by NASA during its early years. The first telescopic images of earth taken by astronauts in space were with a Questar 3.5” from a Gemini spacecraft. The Apollo astronauts used Questars on their missions to the moon as well.

Questars have been popular with many well-known scientists and other personalities; Wernher Von Braun purchased one in 1959. [5]. Talk show host Johnny Carson, well known as a fan of astronomy, purchased an early model. Today Show founding host Dave Garroway and Arthur C. Clarke are other well-known owners.

For a while Questar sold a shorter f/7.8 version of this optical tube assembly to be used as telephoto lens called the Questar 700.

A 7-inch model was later developed, but because of its high price compared with other telescopes in its class, it has never been a big seller. In recent years, Questar re-designed its 7-inch model and re-named it the Titanium Light Weight Classic Seven. This is produced in a classic version (including the control box) and in an Astro version that has a standard visual back.

While it was produced in very limited numbers, Questar also offered a 12" version, typically coupled with an equatorial mount based on a Byers drive system.

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).