Questar Birder, 90mm, broadband coatings, Zerodur mirror, 40/60x, finder, rapid focus, case


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This is it. The broadband-coated/Zerodur mirror Questar Birder is the ultimate spotting scope . . .
Our Product #: QBBZ
Questar Product #: 10312

Product Description

This Questar Birder with broadband optical coatings and a Zerodur mirror is a "legendary" Questar Field Model specially optimized for birding in extreme climate conditions by the addition of a large aperture wide-field refractor-type finder, faster focusing, high light transmission broadband optical coatings and silver mirrors for the brightest possible images, and a thermally stable Zerodur ceramic mirror. It is the spotting scope everyone turns to when the identification of a distant bird hangs in the balance. The Birder has an ultra-sharp 40x eyepiece that converts to either a 60x eyepiece or a wide-field 8x finderscope at the flip of a lever. Other optional higher-power eyepieces are available, as well.

The large aperture 8x refractor-type finder has a wide 300' field of view. The finder is built under the barrel of the scope, rigidly and permanently aligned with the main optics and located safely out of the way. The scope's 40x eyepiece operates at 8x when viewing through the finder. A simple touch on a lever at the rear of the scope instantly switches between the 8x finder and the 40x main optics, so you never have to move your head from one eyepiece to another and chance losing the bird as you do with scopes that have a separate finder. Touch another lever and the magnification instantly increases to 60x. The Birder also includes the 24-turn fast focusing mechanism that's normally optional with the Field Model. The faster-acting 24-turn focusing is a helpful feature for more quickly tracking moving birds and wildlife. The Birder has quickly-removed soft black plastic dust covers for the objective lens, finderscope lens, and eyepiece.

This broadband-coated Zerodur Birder includes high transmission/low reflection 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 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. The broadband coatings package gives you a full 22% gain in light transmission and contrast that's very useful for twilight viewing and photography. The thermally-stable Zerodur ceramic mirror is perfect for critical photographic situations that don't allow focus changes during wide temperature swings. This is helpful for use in difficult locations such as the Arctic or Sahara, but is usually not needed in the continental United States or Hawaii, as well as in most of Canada. The Zerodur mirror offers no other optical advantage, other than the thermal stability, so this Zerodur version of the Birder would be a case of overkill for most birders. The somewhat less expensive broadband coatings/Pyrex mirror version of the Birder (Questar model #QBB) will be more than adequate for 99% of all birders.

However, the broadband coatings package (either this Zerodur mirror version or the Pyrex mirror version) is not recommended if you live full time on ocean-front property, or spend much of the year birding 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 spotting scope's future, consider the Birder with standard optical coatings (Questar model #QB), 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.

All other basic specifications and features of the Field Model remain the same with this Birder - a built-in Barlow lens to increase eyepiece magnification at the flip of a lever, a slide-on metal lens shade, a basic camera coupling set (needs a Questar T-ring), waterproof carrying case, etc.

So, just how good is the basic Field Model that this scope is based on? One of our customers from Nebraska called up shortly after he received his Questar Field Model to say his scope clearly showed the power line into his neighbor's house. We didn't think that was all that impressive - until he told us his neighbor lived three miles away! As a review in Audubon magazine noted, "Brighter than reality, the Questar has unbelievably sharp resolution and an extremely flat field. It shows every feather from a half-mile away!" (The exclamation point is theirs.)

A Questar has no astigmatism or chromatic aberration - no optical problems of any kind - to detract from your enjoyment. The Audubon review added, "the Field Model is unrivalled as a catadioptric spotting scope. It sets the highest standards for both optical performance and convenience of use."

A review in Cornell University's Living Bird magazine said, "The legendary Questar. There's no question that for the right application this is a fantastic scope."

And just what is the right application? According to the Living Bird review, "there are times when the Questar is indispensable. During the World Series of Birding, the Lab team spied a white blob on an old water tower. Rick put his trusty Bushnell Spacemaster on it at 22x - still a white blob. Kevin tried the Kowa TSN-4 at 60x and saw a white blob that might be a large bird. Finally Todd trained the Questar on it, flipped to 80x, and got a crystal-clear image of a roosting barn owl."

What is the right application? It is any birding challenge where you need absolutely razor-sharp views of distant birds and a high power finderscope to let you locate those distant birds. The supplied standard equipment eyepiece gives you a basic 40x magnification. A built-in 1.5x Barlow lens increases that power to 60x at the touch of your finger on a lever at the rear of the scope. Another lever instantly converts the 40x eyepiece to an 8x finder with a wide 5.7 degree field of view (300' at 1000 yards). You never risk losing your subject as you move your eye from finder to eyepiece, because finder and eyepiece are one and the same.

For those birders who prefer higher powers, an optional 53x eyepiece is available that provides 80x when the built-in Barlow is used. The 53x eyepiece can be substituted for the standard equipment 40x eyepiece at no extra cost, if the substitution is requested at the time your scope is ordered. The 53x eyepiece is also available for separate sale, to give you a total of four separate magnifications from only two eyepieces (using the scope's built-in Barlow lens to increase the power of each eyepiece). A rolldown rubber eyecup is provided on all eyepieces for eyeglass use, although eye relief is relatively limited at higher powers. (The standard 40x eyepiece has a good 15mm of eye relief, however.)

Because of its high power and its ability to focus as close as 20' (although with a very shallow depth of field at that close a distance), the Birder is a marvelous long distance microscope for close-up studies of subjects that are too small or too dangerous or too fragile to examine at close hand - ant hills, bee hives, spider webs, etc. At its standard 40x magnification, subjects 20 feet away appear the same size as they would if you could get your eye within a mere 6" of them, with a field only 4.6" wide filling your eyepiece! Imagine your views of gape-mouthed chicks being fed in nearby nests, hummers at feeders, and more!

The black and satin-finished aluminum Birder comes with a quickly-removed heavy black vinyl protective dust cap. Similar caps are provided for the finderscope's objective lens and eyepiece. A slide-on metal lens shade improves both visual and photographic contrast. Other standard equipment includes a camera coupling set that lets you use the Birder as a razor-sharp 1400mm (28x) f/16 telephoto lens by adding an optional Questar brand P-thread T-ring to fit your particular camera body.

An optional roof prism image erector, #6351, is available to allow straight-through viewing (from inside a car being used as a mobile blind, for example, using an optional car window mount). There is a loss of field when the image erector is used (from 58' down to 47' with the 40x eyepiece), the lever that changes from finder to a high power view is disabled, and you can only change powers by changing eyepieces, as the Barlow and finder optics are no longer in the optical path.

A foam-fitted waterproof hard case is standard equipment.

Ten-year Questar warranty (two-year warranty on the focuser, five years on the broadband coatings).

As the review in Audubon concluded simply, "Questar is superb." If you want the world's very best spotting scope, a Questar is it. Period. Case closed.

Tech Details

Aperture 3.5"
Armored No
Exit Pupil 2.2mm @ 40x
Eye Relief 15mm @ 40x
Field of view 1000 yards 58' @ 40x
Length 11"
Magnification 40 & 60x
Near Focus 20'
Photographic Focal Length 1400mm
Photographic Focal Ratio f/16
Twilight Factor 59.7 @ 40x
Warranty 10 years


Review by:
I purchased the Questar birder scope with the broadband coatings and the low expansion (Zerodur) mirror. I must honestly say if there is a better scope out there particularly for birding I'm not aware of any period. I can say without reservation this is the ultimate birding scope. Case closed! (Posted on 1/8/2021)
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