With the factory-installed addition of the normally-optional battery-operated Powerguide III drive system, the standard Questar 3.5" Maksutov-Cassegrain becomes a world traveler . . .
In 1950, Questar introduced the first truly portable, lightweight, 3.5" astronomical telescope. Regarded as the finest personal telescope in the world, the 3.5" Questar Standard Maksutov-Cassegrain was legendary for its resolution, flatness of field, and contrast. While today's 3.5" Questar outwardly appears virtually identical to the 1950 original, natural evolution and new technologies have improved even its legendary performance. Today, as in 1950, Questar once again sets the highest standard for optical performance in a truly portable personal telescope, with integrated features that are unavailable with other telescopes.
What is it about a Questar that makes it the best?
Simply this: a fanatical devotion to hand-crafted accuracy.
Hundreds of hours of painstaking, skilled effort and the finest materials available go into producing this optical and mechanical masterpiece. As a Rolls-Royce is to automobiles, so is a Questar to telescopes - the very finest hand-crafted optical performance that money can buy.
What are costly options with other scopes - a glass solar filter, a premium Barlow lens, two premium eyepieces - are all standard with a 3.5" Questar. Also standard are amenities that are simply unavailable on other scopes - a glass solar filter for the finder, an accurate star chart on the self-storing dewcap that slides forward to reveal a useful map of the Moon on the optical tube itself, and a velvet-lined carrying case.
The 3.5" Questar is a complete telescope in a seven pound package. Remove it from its luggage-quality Naugahyde case (or optional leather case), attach the tabletop tripod legs stored in a pocket in the door of the carry case, place it on a table, and you have all the user-friendly controls of a great observatory scope at your fingertips.
Unscrew the dust cap, and you can begin to appreciate the attention to detail lavished on a Questar - for the dust cap is not flimsy press-fit plastic, but solid machined aluminum that threads into the barrel to afford absolute protection to the optics.
Look into the Questar's premium 24mm Brandon eyepiece and you're looking into a 4x finder with an exceptionally wide 12° field. A finger touch on a convenient lever at the rear of the scope changes the finder into a 53x telescope for observing the Moon, nebulas, and star clusters. Touch a second lever and a built-in Dakin Barlow instantly increases that eyepiece power to 80x for closer observing. Exchange the 24mm eyepiece for the supplied 16mm Brandon eyepiece and you extend the power range still further, to 80x and 120x. And optional higher and lower power eyepieces are available, for magnifications as low as 40x and as high as 320x. For observing comfort, a rare thing with many scopes, the eyepiece tilts from side to side to the most convenient observing position.
Observe through a Questar, and you'll appreciate the attention to detail even more. The gearless 25:1 ratio slow motion controls operate with a smoothness and freedom from backlash unmatched by any other amateur telescope. The drive gear diameter is fully half the length of the telescope itself, for tracking precision that must be experienced to be believed. No tiny levers need be thrown to disengage the drive for manual operation, as a butter-smooth internal clutch made from micro-rolled discs of stainless steel lets you move the telescope at will. The large setting circles are not merely painted on, but are engraved and then paint-filled, to remain visible even after years of use. 'Jewel-like precision' may be an overworked term, but it's the only one that does justice to a Questar.
The normally-optional Powerguide III DC drive system/drive corrector that is factory-installed into this Questar eliminates the need to stay near an AC power outlet to operate the scope's motor. The Powerguide III replaces the standard Questar's 110 volt AC drive with a DC servo quartz drive that powers the scope's drive motor for up to 50 hours from a single 9 volt transistor radio battery. This frees you forever from the need to stay near an AC outlet to observe the skies. The Powerguide III will smoothly track the Moon, planets, star clusters, galaxies, and a host of other deep space objects across the heavens for you, keeping them centered in the eyepiece all night long. During the day, the Questar will also track the Sun, allowing you to observe sunspot patterns. You'll do it in complete safety, as standard equipment glass solar filters provide complete protection against the Sun's fierce radiation for both your eye and your telescope.
Pushbuttons on the quartz-controlled Powerguide III hand control allow single axis guided astrophotography with 1.4x and 10x sidereal guiding rates in right ascension (dual axis with an optional declination motor). Other buttons control a built-in map light and the brightness of an optional illuminated reticle guiding eyepiece, and select either a lunar or sidereal drive rate. Another button selects northern or southern hemisphere operation, allowing you to use the Questar anywhere in the world without having to worry about finding the proper power frequency or voltage, or having the right kind of AC adapter. The Powerguide III hand control stores neatly into a pocket in the door of the carrying case when not in use. With the factory-installed Powerguide III, the Questar is truly a use-anywhere/anytime telescope!
High transmission/low reflectivity magnesium fluoride coatings on both sides of the scope's BK7 corrector lens are standard on this Questar. The option of replacing the magnesium fluoride coatings on the corrector lens with broadband dielectric multicoatings during manufacture (which also includes a change of mirror coatings from aluminum to silver) is also available. This option gives you a full 22% greater light transmission for deep space viewing, and higher lunar and planetary contrast. (Broadband coatings are not recommended if you live by the seaside, as the silver mirror coatings can be adversely affected by constant exposure to salt air.)
A thermally stable Zerodur ceramic mirror is also available as an option in place of the Questar's standard Pyrex mirror for situations involving large temperature swings. As with any Pyrex mirror telescope, if the difference in temperature between indoors and outdoors is 30 degrees or more Fahrenheit when a Questar is taken outside, minor refocusing will be required as its mirror contracts while cooling down to the outdoor air temperature. Although the 3.5" mirror of the Questar cools down much more rapidly than a larger mirror, some people find the need for even an occasional refocusing to be annoying. Since a Zerodur mirror exhibits virtually no expansion or contraction as temperatures change, this option eliminates the need for refocusing, should this be a concern.
This Questar is protected by a ten-year Questar warranty (two-year warranty on the focuser mechanism).
Absolutely pinpoint resolution, total freedom from spurious color and distortion, with an image clarity and contrast in a class all its own - a Questar is truly the Rolls-Royce of telescopes. If you want the best small telescope in the world, Questar is it. Period.
