I have had my scope about 3 years now. Last night was the first time that I got a good focus at the beginning of the session but by the end of the session only 2 hours later, the scope was pretty far out of focus. Anyone else run into this problem after only 2 hours? Thanks. Jim
I don't think it is focus. More likely cooldown and changes in seeing. I find the need to fine tune focus frequently throughout a night depending on atmospheric conditions and what part of the sky I may be aimed at.