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Old 13-07-2019, 04:34 AM
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Don Pensack
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Don Pensack is offline
Join Date: Aug 2006
Location: Los Angeles
Posts: 402
Originally Posted by thegableguy View Post
apologies for asking a question i'm sure has been asked dozens of times, but, well, i'm lazy...

Considering getting a 2" ep or two. Please correct my understanding if it's wrong, but is looking through a 30mm 2" eyepiece similar to looking through a 30mm 1.25" except with a larger field of view? Ie same magnification, targets will look about the same size - you can just see more of the surrounding sky?

Yes, that's true. But that makes all the difference in the world because along with the larger true field comes a larger apparent field.

Is it a markedly nicer experience to look through a 2"? My little girls kinda struggle to line their eyes up in the right place.

Any difference in relative brightness between the two? (i would expect not, but maybe...?)
no, because exit pupil (brightness) is related to the eyepiece's focal length.

Are they sharp to the edges, or do they get blurry? Or maybe that depends on the quality of the ep in question?
It depends on the quality of the eyepiece. If you want to have a 30mm with wide field that is sharp to the edge, expect it will be large, heavy, and expensive.

Does it matter much what kind of telescope you're using a 2" ep with? Ie would there be a lot of noticeable vignetting or any other issues with a basic 8" f/5 reflector?
It does matter, but it won't be a problem in that telescope.

Any other info would be great. I've just dusted off my telescopes after several years' neglect and am hoping a few nice new 2" eps / barlows will get me off my bum and looking & imaging through them again.
If you get an ultrawide 30-31mm eyepiece, be prepared to enjoy it enough you will soom be changing all your eyepieces.

my answers are above, in BOLD.
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