Normally this is my rule from observing from windows. This is from my experience of owning all the designs beforeacc wrote:I personally do not experience any problems viewing from my balcony with either of my scopes. I guess condition varies from place to place and YMMV. Cheers!My personal experience mirrors weixing's opinion in that one should not view through a window. I was using my 5" SCT and did experience significant distortion.
1) Small refractor -----> No impact on image. Can observe almost immediate
2) Small and mid-size reflector (close tube) ----> leave window open for about 30 minutes before observation, no impact on image
3) SCTs and Maks (5-8") -------> Leave window open about 1-1.5 hours before observation, minimal impact on image
4) Truss tube reflector ------> Leave window open for about 15 minutes, minimal impact on image.
In all cases above, scope should be next to the window throughout the "stabilising period"