: No firsthand experience, but some comments and : questions if you don't mind. What size / kind of scope : are you using? What types of observing do you : plan on? For a large scope, and mostly planetary : views, you could probably get away with it. For : deep sky observing of faint objects you're going : to loose a lot of light - which gets costly REAL quick. : Hassles are: reflection of outside surface, interference : on outside surface from surrounding light pollution, : thermals as you mentioned, and refelction from the inside : surface backinto the scope. IMO, I'd go for a "small" : opening, try to ven the heater to prevent thermals, : but go with open sky... but that's me.. : Let us know what you do!

I've got an 8" Omcon and I'd like to do all types of observing, at least until I have enough experience to know if I will have a preference.

I know open-to-the sky is the way to go but for the past week we have had daytime highs around -24dC and lows around -31dC BURR!! - so the scope has sat in the corner even though the night sky is India-Ink black and the stars are incredibly bright.

My thinking is thus - if you can make a lense for the front of a refractor, why can't I have a "double-planar lens" in front of my reflector?

I will probably build my obs so I can have a removable window. When conditions or objectives permit, I'll use glass. For critical viewing, I can open the window.

• Re: Observatory window? - Dave/">Dave - January 9, 1999 - 13:37 UTC
  • Re: Observatory window? - eric/">eric - January 14, 1999 - 10:29 UTC
    • Re: Observatory window? - Dianne - January 15, 1999 - 08:47 UTC