Questar Corporation
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| Questar Corporation | |
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| 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" of astronomical instruments.[1][2]
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[edit] Origins and history
Questar was founded in 1950 by Lawrence Braymer who set up Questar to develop and market Maksutov telescopes and other optical devices for the consumer, industrial, and government customers. The Questar Standard telescope has been in production since 1954 probably making it the longest running production consumer oriented telescope.[citation needed]
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 Cumberland Optical.[3] The optics are hand-aspherized.[citation needed]
Questars have been popular with many well-known scientists and other personalities; Wernher Von Braun purchased one in 1959.[4] 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.
[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” aperture 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.
- While it was produced in very limited numbers, Questar once offered a 12-inch-aperture optical-tube assembly. Some barrels were sold coupled with an equatorial mount based on a Byers drive system.[citation needed]
[edit] 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).[citation needed]
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 focal 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, Scientific American and Sky & Telescope. 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. The Questar of the 1950s and early 1960s offered little capacity to employ third party accessories although there was a range of accessories made by Questar itself. Later models have the added advantage of accepting standard 1.25" eyepieces and other accessories.
A 7-inch model was introduced in 1967 for industry and government. It appears as a scaled up Questar 3-1/2" with the integrated Control Box. But because of its high cost compared with similar-aperture consumer telescopes, the Seven has never been a big seller among the amateur market.[citation needed]
Versions of the Questar 3-1/2" were used by NASA during its early years. The first telescopic images of earth taken by astronauts in space were with a Questar 3-1/2" from a Gemini spacecraft. The Apollo astronauts used Questars on their missions to the moon as well. For camera tracking of launches, NASA still uses 12 inch Questar telescopes mounted on an anti-aircraft gun mount, in the style of the original rocket tracking systems used at White Sands, as invented by Clyde Tombaugh, the discoverer of Pluto.[citation needed]
Since the telescope is made in a small production run by a relatively small company, the economies of scale have meant that the Questar 3-1/2” comes with a high price tag. Also the basic design has been remained almost static since its first production. For use in the field of amateur astronomy where resolution and light-gathering power are the primary requirements for a telescope, the Questar 3.1/2's comparatively small aperture has led the instrument to be to criticized as being too small and too expensive,[5] especially in a market where instruments more than twice its aperture are available at half its price.
This model was originally envisioned as a 5 inch 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.[citation needed]
[edit] References
- ^ Astronomy - Partial Eclipse of the Setting Sun - "My other small telescope is a Questar, the classic Maksutov that for fifty years has been a kind of Rolls Royce for amateur astronomers."
- ^ Questar - birder 90mm - "Questar is truly the Rolls-Royce of spotting scopes"
- ^ J.R. Cumberland, Inc - Questar
- ^ Kennedy Space Center's Amateur Astronomers' "A TELESCOPE FROM HISTORY OWNED BY DR. WERNHER von BRAUN"
- ^ Joe Bergeron's Astronomy Equipment Reviews - Questar 3.5"
