http://www.iceinspace.com.au/forum/s...ead.php?t=5541
we have an experiment going on as we speak re temperature.
not sure if this will work
http://www.iceinspace.com.au/index.p...0ba8bc92010a63
this is a hartmann mask to help you focus when you cant look thru the eyepiece (ie imaging).
basically you cut holes ie three circles in a piece of cardboard and then put that over the opening of your scope. you cut down the light, but you will still get an image!.
asimov, ving and others have some great piccies of them. different shapes have been cut