I have two scopes that I use at the moment: the Saxon ED80 and the GSO Dob 200mm/8".
When I go away for a night of dark sky observing, the ED80 does not get much of a look through. But at home the ED80 is getting a lot more use than the Dob. This is partly because I can use the ED80 instantly without waiting for cooldown, but more importantly that even if I do wait for the Dob to cool down (for up to 2 hours), it never comes close to the refractor on "seeing". After having seen Bird's demonstrations of how small temperature differences can affect what you see through the EP, I'm thinking maybe my Dob never reaches thermal equilibrium with the surrounding air. So, for medium to large aperture viewing I want an active cooling system like Bird's.
But for use at home on weeknights I think I might be better served by something that works perfectly without batteries or any other power source. Now, my ED80 exceeded all my expectations for an 80mm aperture scope. But since most of my light-polluted backyard observation is aimed at the planets, I find the aperture a somewhat lacking in light gathering power at high magnifications. So I'm thinking of maybe upgrading to the ED100 (Saxon/Orion/etc) or some other similar scope.
I don't recall seeing any ED100 owners on these forums. And reviews are hard to come by. The ED80 seems to far outsell the ED100 everywhere. I'd hate to sell my ED80 to finance an ED100 (worth two ED80s), only to find out the ED100 is just not up to the standard of the ED80.
Do you have some experience with the ED100? Or do you know of a similarly priced apo or semi-apo 100+mm refractors around? Or do you have advice on what is a good weeknight backyard scope? Or do you just want to knock some sense into me after reading all this drivel? I'd love to hear from you.
