Camera to 80ED Refractor

Take a clean white t-shirt and place it over the end of the OTA

Ahhh, heard of that alright, I just thought it was initially some nutty idea
I'll do that so.

Dave L, thanks for that point, much appreciated

Keith..

Keith,
Take this from someone who knows, dont use the 1.25" barell with the 300D, you WILL get a lot of vignetting. The only difficulty of mounting the t-ring onto the 2" thread on the back of the scope is that you cant use filters. Get a 2" t-thread adaptor tube which allsows 2" filters to be screwed into it. However you probably wont need filters unless you modify your 300D anyway

Thanks Dave ! I had planned on using my 2x barlow (after all - it is a t-adapter with a lens!) just to magnify what i'm shooting e.g galaxies, so maybe vignetting would'nt be such a problem if I have my target centered?

Keith..

Hmm why do that Keith?

With a 2x barlow lens on an ED80 your exposures are going to have to be mighty long given that this makes an 80mm scope F/15!

Using an f/6.3 focal reducer on your C8 gives a local lenght of 1260mm at f/6.3 almost the same as an ED80 at 1200mm with the barlow.

You dont need the barlow to get image scale on galaxies etc. You'll be amazed at just how big these things blow up with the 300D's resolution.

With a 2x barlow lens on an ED80 your exposures are going to have to be mighty long given that this makes an 80mm scope F/15!

:shock: Whoops, I actually did'nt know about that Dave, thanks for letting me know, I just thought that since the scope is f7.5, the field of view would be too big for galaxies and other small targets.

All the better!!

Keith..