by Michael and Diane Porter
Questar Field Model 3.5 and Questar Birder 3.5
60x resolution score: 20 F
In our resolution tests, the Questar surpassed everything else. By focusing
the image with a mirror instead of a lens, Questar avoids creating chromatic
aberration and produces razor sharp images and especially vivid colors.
Furthermore, the compactness of design reduces vibration.
Design of the Questar
You look down at a 90-degree angle into the eyepiece. Two levers on the
back of the scope let you switch among 3 levels of magnification. With
a 32mm eyepiece on the Questar Field Model, you get 3x, 40x, and 60x.
The 3x functions as a wide-angle finder.
Center what you want to see, flip the lever to increase the magnification,
and focus. There's your bird, in stunning clarity. The 32mm eyepiece has
enormous eye relief (over 60mm) even at 60x, so this scope is a boon to
eyeglass wearers. A variety of other eyepieces are available.
Two Questars for Birders
Two models of Questar are appropriate for birding, the Questar Field
Model 3.5 and the Questar Birder 3.5.
With the Questar Birder, the 3x finder is modified to 8.5 power, and the
focusing is 2.5 times as fast. The rapid focus modification is optional
on the Field Model. Options for both models include Broad-Band & Low Reflection
Coatings, to increases light transmission 22% and improve contrast, and
the Zerodur mirror, more thermally stable than the standard Pyrex.
The higher power finder in the Birder model prevents the scope from rotating
in its mount. However, the Field Model rotates and allows viewing from
more comfortable angles. The authors recommend, for birding, the Field
Model 3.5 with the Broad-Band coatings, the rapid focus modification,
and the 32mm eyepiece. If you bird in a cold climate, then add the Zerodur
Limitations of the Questar for birding
The Questar is not designed for rough service, as the specialized birding
scopes are. It's not waterproof, and it needs protection from weather
and dust. The Questar produces an image that is reversed left to right,
because it does not use erecting prisms to flip the image into the normal
position. Some birders do not mind the reversal or get used to it for
the sake of the outstanding sharpness of this scope.
The Scopes at a Glance - A Chart
Here we tabulate the essential specs on all the scopes we tested and their
Policy | Basic optics page | The Binocular Advisor
| Binoculars Glossary
| Gifts for birders
Home FAQ Tips