Questar Adapter Telescope Accessories > Questar Adapter > Questar 3.5
Getting the Most From Your Questar 3.5

The aperture opening in Questar eyepiece holder limits the true field of view in eyepieces with large field stops. However, compared to the 24mm Questar supplied eyepiece, the Tele Vue 19mm Panoptic has 17% wider true field and the 24mm Panoptic has a 30% wider true field, even with vignetting limiting its potential.

Overall, we recommend the Delos 10mm and Panoptic 19mm. While all 1¼" TVO eyepieces can be used with the Questar, only the following will focus in the finder mode and offer parfocalization (no need to adjust focus when changing eyepieces) as well.

Tele Vue Eyepieces That Focus in Finder and Telescope Mode
Eyepiece   Finder Mode   Telescope Mode

Plössl 25 50   4.3 11.4   52.0 0.93
20 50   5.4 9.2   65.0 0.75
15 50   7.1 6.7   86.7 0.56
11 50   9.7 4.9   118.2 0.40
8 50   13.4 3.5   162.5 0.29
Panoptic 19 68   5.6 11.4   68.4 0.94
Delos 10 72   10.7 6.8   130.0 0.56
6 72   17.8 4.1   216.7 0.33
Key: FL = Focal Length, AFOV = Apparent Field of View, Mag. = Magnification &, TFOV = True Field of View.

Questar 3.5 and Bino-Vue — Extraordinary

Using the Tele Vue Bino-Vue body, the full potential of 24mm Panoptics are realized, without vignetting limitations. Refocusing the Questar for Bino-Vue results in the Questar increasing its focal length by over 40%. Amazingly though, the now unleashed 24mm Panoptics have so much field that the true field is still larger than with the standard Questar 24mm eyepiece in normal mode. Of course, the Bino Vue accepts all 1¼" Tele Vue eyepieces: Plössls, Panoptics, Naglers, Delos and Ethos.

Questar and Ethos 13mm — Looks are Deceiving

A customer asked us to check out this combo. Compared to the Questar supplied 24mm Brandon eyepiece, Ethos produces almost twice the power plus 1/3 more true field area.

It may be the only eyepiece a Questar owner needs: 100x / 200x with Questar Barlow. Note that Ethos 13mm, 10mm, 8mm, & 6mm will focus, but not in finder view.

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