Telescope Definition and 506 Threads

Reading the article at http://www.msnbc.com/news/961142.asp?0dm=C13NT I saw that it said the new scope needed about a month to cool down to optimal operating temperature. Why would it take a month? E6S

This is not a homework question but I am posting it here because I think it may be too basic for the other forums. I am looking for a ray diagram for a reverse galilean telescope (ie. + eyepiece, - objective, so image is minified). Can anyone describe what the ray diagram would look like or...

I need tips on how to slow down a fast telescope. I've heard of showercaps, endcaps, and dustcovers; but what I need are details on how to construct a good quality piece that will stop down the aperture.

http://www.ehobbies.com/1004-2786.html I know a person who is selling this telescope for $300 used. He says it's in great shape. But I hear these telescopes are made cheap using cardboard and stuff. Anyone have experience or comments about them? I have a cheap-o 60mm refractor telescope...

well I am looking to buy a telescope... I want something with power.. I live somewhat near NYC (about 40 min) so I get a lot of city light in the sky... what do you guys think of this other than the fact that it weighs a lot.. its not something I would be lugging around.. only on rare...

I'm fixing to buy a telescope. I saw one in the Discovery Channel Store at the mall that has a digital camera. Are there any other sexy features on telescopes that I should know about? What are some good buys?