Ian, Anything less than 3" at a minimum would be generally ineffective for very much. Since you're in a light polluted area, even that can be very small. Portable instruments have been made to some amazing sizes. Consider an Astroscan (5" I think) for a start. It is a very short FL unit that can be handheld for quick views and is quite sturdy and can be pretty much banged about a bit. There have been Cass. scopes that set up in seconds and can be carried in a big fannypack type of case. One fo the famous Amateurs (can't remember his name at the moment) made one many years ago which was a pretty naked set of optics and support for the secondary. If anything, if I was going to make a superportable instrument, the Cass. design allows for pointing and looking at the same direction. The only problem with that design is that anything less than about F8 gets to be rather hard to make and keep aligned well. My best suggestion is to find a small dob type scope that your prof's will allow in the area of the work enviroment. Stargazer Steve just came out with a 6" which is on a tripod and is probably very good for your uses. You might also consider some 15x20 or up to 20x80 binocs. That's my ideas on the subject. Have Fun and Keep Looking Up! Bob May

• Re: Very small mirrors - David_Sinden/">David Sinden - September 12, 1998 - 09:27 UTC
  • Re: Very small mirrors - bobmay - September 15, 1998 - 21:34 UTC
    • Re: Very small mirrors - Jose_Henrique_Schreiner/">Jose Henrique Schreiner - September 26, 1998 - 20:34 UTC