Quote:
Originally Posted by mtfreestyler
Ok so I have loaded the ED80 and the Star71 into Stellarium and have been comparing the 2 against all the well known nebulae to see what would suit better.
The ED80's 600mm looks like a great focal length and I'd like to be around there but if I get a Barlow could I use that on the Star71 to make it a 700mm scope?
What else would you shoot at a FOV around 6 degrees?
I think having the 7D with a crop sensor will help as well to get different effective focal lengths
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possibly you could, although I am not sure it is worth the effort.
focal ratio goes out to f 9.8, how good is the barlow glass you're putting in there ...? other potential issues adaptors? vignetting?
how are you guiding? OAG? standard camera lenses are quite capable of superb widefield already particularly when on a GEM.
eg done with an 85mm lens (mosaic)
http://www.iceinspace.com.au/forum/s...d.php?t=130260
I wouldn't worry re the ED80 it is plenty good enough; here is the most recent ED80 pic on the forum (DJScotty) - taken in narrowband
http://www.iceinspace.com.au/forum/a...e.php?a=176998
for the purpose of showing an 8" newt here is one of the same object - taken with dslr
http://s1172.photobucket.com/user/jt...ml?sort=3&o=70
I would take on acropolite's recommendations - but then again if it were me i'd get a 8"newt and put the money into a proper astro camera
cheers