Questar 3.5" Standard, Broadband Coatings, Zerodur mirror

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$5,875.00

Availability: More on the way

The best optics, the best optical coatings, the most performance per inch of aperture, the most features - if you want the world's best 3.5" ultra-portable telescope, look no further. This broadband-coated Zerodur mirror Questar is the ultimate . . .
Our Product #: Q3BZ
Questar Product #: 10314
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Product Description

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.

Plug a Questar into a 110 volt 60 Hz household AC outlet and its built-in drive smoothly tracks the Moon, planets, star clusters, galaxies, and a host of other deep space objects across the heavens for you. 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.

An optional Powerguide III DC drive system and drive corrector will power the Questar drive motor for up to 50 hours from a single 9 volt transistor radio battery, freeing you forever from the need to stay near an AC outlet to observe the skies. Pushbuttons on the quartz-controlled Powerguide III hand control allow single axis guided astrophotography with drive corrections at 1.4x and 10x the sidereal rate. Dual axis drive correction is possible by adding 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 the right kind of AC plug. The Powerguide III hand control stores neatly into a pocket in the door of the carrying case when not in use. With a Powerguide III, the Questar is truly a use-anywhere/use-anytime telescope!

This broadband-coated Questar includes ultra-high transmission/low reflectivity broadband dielectric multicoatings on both sides of its objective lens for a light loss of less than 1/10th of 1% per surface for the brightest possible images. This compares with a light loss of 1% per surface with standard magnesium fluoride antireflection coatings. This multicoatings package also includes high reflectivity silver mirror coatings with a protective overcoating of thorium fluoride instead of standard aluminum coatings with a silicon monoxide overcoat, for an additional improvement in light transmission of 10% per surface. The broadband coatings package gives you a full 22% overall gain in light transmission and contrast that's very useful for photography and when viewing faint deep space objects.

This broadband coatings package is not recommended if you live full time on ocean-front property, or spend much of the year at the seaside. Constant exposure to salt air can adversely affect the silver mirror coatings. Occasional visits to the shore are not a problem, only extended stays (particularly if the scope is not packed away in its case when not in use). If prolonged exposure to salt air might be in your scope's future, consider the Questar with standard optical coatings (Questar model #Q3), rather than this broadband-coated version. You will lose some light transmission, but will gain a measure of optical coating longevity. Adding a few packets of desiccant (silica gel or similar, available at most camera stores) to the case of any spotting scope to absorb moisture when near large bodies of salt water would be a helpful preventative measure in any event.

The scope's thermally-stable Zerodur ceramic mirror eliminates the minor need to refocus the scope as it cools to ambient temperature in situations involving large temperature swings. With a conventional Pyrex mirror telescope, if the difference in temperature between indoors and outdoors is 30 degrees or more Fahrenheit when the scope 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, the Zerodur mirror in this scope eliminates even the need for minor refocusing, should this be a concern or an inconvenience.

This Questar is protected by a ten-year Questar warranty (two-year warranty on the focuser mechanism, five years on the broadband coatings).

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.

Tech Details

Aperture 3.5"
Binary and Star Cluster Observation Good
Focal Length 1300mm
Focal Ratio f/14.6
Galaxy and Nebula Observation Fair
Heaviest Single Component 7 lbs.
Highest Useful Magnification 162x
Lunar Observation Great
Weight 7 lbs.
Planetary Observation Good
Resolution 1.3 arc seconds
Telescope Type Maksutov-Cassegrain
Visual Limiting Magnitude 12.2
Warranty 10 years

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Supplied Accessories

  • 1.25" 16mm and 24mm eyepieces (54x to 120x, depending on eyepiece and whether built-in 1.5x Barlow is used)
  • Built-in 4x finder (6x when 16mm eyepiece is used)
  • VHR silver coated and overcoated Zerodur glass ceramic mirror
  • Broadband dielectric multicoated optics
  • Built-in star diagonal
  • Dual arm fork mount
  • Setting circles (r. a. circle power driven)
  • Sidereal rate AC motor drive (2.7 watts)
  • Manual slow motion controls
  • Thread-in dust cap
  • 1.5" aperture off-axis solar filter
  • Solar filter for finder
  • Tabletop tripod legs
  • Locking hard case
  • Self-storing dewcap with embossed star chart
  • Embossed Moon chart on scope barrel
  • Ten-year warranty (two years on drive and focuser)