a complete design?

[Harry Roberts]

Questar probably had the best design yet for a field solar observatory. I have captioned this to show how advanced it was - something we are unlikely to ever see again. This was (still is?) a standard set-up for the serious sunwatcher. They solved a number of problems. Accurate finding and pointing. Variable focal lengths FL , variable waveband and variable prefilter apertures were available at the pointing ep. There is a sunshield to protect the viewer. I once (briefly) used a seven inch Questar - it was rugged and refined at the same time. Fork mounts are ideal for the sun as access to the poles is not needed - no counterweights needed. The detector and eyepiece move through a very small arc throughout the day, no need to "tumble" the whole thing at midday.
They solved a great many problems in this piece of gear around 1970! And the Mak design put a 1300mm FL in a very short tube - with a 2x Barlow built in. Ive added the captions. The pic is for discussion of issues - Ive never actually seen this setup in use.