Big Bertha 2.0: We're Getting There!

Big Bertha 2.0: We're Getting There!

I spent some time today checking collimation, and I am finally happy with the results. There is still a little bit of miscollimation as I move the telescope from horizontal to vertical, but it isn't ferocious. If I collimate with the telescope at about a 30 degree angle, moving it to vertical produces very little change, and horizontal isn't really one of the more useful directions for an astronomical telescope. If I could identify the source of the bending, it might be worth trying to get this a bit better--but with the inherent limitations of this turned edge mirror, it may be polishing a cinder.

I also experimented with the light shroud. The purpose of a light shroud is to keep straight light from hitting either the main mirror or the diagonal mirror. Under night conditions, there is usually almost no stray light anyway; light that hits the main mirror from any direction from straight on will be reflected off to the side, anyway. The place where a light shroud is of greatest value is when you are using the telescope at twilight, and there is still a bit of skyglow.

Well, I had the telescope in the garage at lunchtime, with the north facing door open. I was using the telescope to examine hillsides several miles away. I couldn't see that the light shroud made any difference--and this is daytime! I won't bother with a light shroud.