Refractor or Reflector – Which is “Best” for Astrophotography?

Started Nov 30, 2012 | Discussions thread
wfektar
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Re: Refractor or Reflector – Which is “Best” for Astrophotography?
In reply to RustierOne, Dec 1, 2012

I'm not going to argue for one or another, only to suggest that it would be a good idea to join a star party sometime. There you can check out all sorts of different scopes, ask questions, and see what works for you.

Or just get something not too expensive (as long as it's not complete crap) and get to know it well. If you lose interest, not a big deal; if you continue on, you won't be satisfied with any one scope anyway.

Just a few notes to add to what Russ said:

Refractors: Achromats have some residual chromatic aberration that won't be an issue unless you look at bright sources. Apochromats have very very little residual color and cost 5-10x as much. Long (higher f-number) refractors are easier to correct for this, but have moment arm issues. No central obstruction means these have the most light-gathering for a primary size (but that size tops out pretty quick)

Reflectors: Newtonians are pure reflectors (excepting the eyepieces) and have no chromatic aberration. Instead you have coma (also worse for faster designs). You can get a coma corrector for this, though.

Cats: Nice compact package, which because of the short moment arm helps with the mount as well. Coma issues (can be corrected).

Personally I lean towards small refractors, because portability is important and the refractor gets the most light/priimary, but that's just me. I like Newtonians least because they're a little fussier with cool-down and collimation, but those are hardly showstoppers, and hey, they're all good. And where the Newt kills the others is photons/$ and $/arcsec. Russ notes that you can get a 14" SCT for less than 1/2 of what you'd pay for a 6" Tak -- but you can get a 17.5" Newt for less than the C14, and the Newt comes with a mount.

BTW,comparing a Celestron to a Tak is hardly fair. Maybe the ES 127 or Meade instead of the Tak 130 (though I've never seen the ES, so perhaps that's not fair either) -- your point still stands but the $$ difference is less egregious. After all there are also gorgeously made and ghastly priced cats as well -- didn't Questar make a 12 once?

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