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scope for my canon T3i

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#1 ky1duck

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Posted 16 January 2013 - 02:25 PM

i am sure this has been posted before. i have a t3i and i am looking for a new scope for it. trying to stay under 600.00. i have been looking at the at72ed.at65edq or the orion 80mm ed. Or sonething around a 8" or smaller fast newt like the AT 6" f4 or the orion 8" f3.9. any ideas or thoughts would be apreacited.

thanks
robert

#2 mmalik

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Posted 16 January 2013 - 03:20 PM

I would suggest the one you have in mind (AT72ED) or AT65EDQ. Read these:

Link1...
Link2...

#3 piaras

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Posted 16 January 2013 - 08:08 PM

I have used the Orion 80ED with the 350D and T3i, other than needing a flatener for the extreme corners, I am happy. I bought it used and it came with the WO Santa focuser upgrade. I also have the Lumicon Deep Sky and Astronomik EOS clip filter CLS-CCD to use depending on whether the scope or EF lens being used.
Pierre

#4 RedLionNJ

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Posted 16 January 2013 - 08:16 PM

Agreed with Pierre, above. For deep sky work, the pixel size is a great match for an 80mm at around F6. You'll likely get close to a 2-degree field. Some kind of field flattener likely would be necessary for the edges, though.

Grant

#5 nofxrx

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Posted 16 January 2013 - 08:20 PM

Get an Astro-Tech AT8IN..AWESOME scope. with an MPCC it will be perfectly flat.
And trust me, having owned both, the AT is MILES above the Orion 8"!

Or the 65Q is also amazing! Best ~$500 I have ever spent...honestly..
and will fully illuminate a Full Frame sensor too if you ever decide to upgrade your camera..

Any of these will easily work on the iEQ45, imho.

Good luck!

#6 Samir Kharusi

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Posted 16 January 2013 - 10:27 PM

Get an Astro-Tech AT8IN..AWESOME scope. with an MPCC it will be perfectly flat.
And trust me, having owned both, the AT is MILES above the Orion 8"!

When doing DSO imaging focal ratio is critical to keeping the length of subexposures short. Hence the decision, IMHO, is whether the purchaser is all that keen on a long focal length (and implied autoguiding). If yes, then the Newt indeed looks like the way to go. If the OP is simply looking for a means to take great DSO images with the minimum of complexities, then a Canon 200mm/2.8L II looks like a great alternative. I have difficulties seeing where a small APO fits in with DSLRs. f6 is way too slow for pleasant imaging (5 minute subs imply autoguiding using in all likelihood a similar small OTA) and the focal length of around 400 to 500mm is still too short to be much use for lunar/planetary imaging. The 70 to 80mm aperture is also too little for visual use. The Newt would make a better deal vs a small semi APO as regards focal ratio, visual use, lunar/planetary imaging and of course focal length for those chasing seeing-limited DSO imaging. A camera lens would make a better deal for unguided DSO imaging (f2.8 implies one-minute unguided subs) and you get a daytime toy too.

Example unguided images using the Canon 200mm f2.8:
Posted Image

with a 1.4x tele-extender, but still unguided:

Posted Image

In brief, for under $1k go Newt or go camera lens, IMHO.

#7 nofxrx

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Posted 16 January 2013 - 10:33 PM

Hmm, never thought about it like that.

I have been meaning to try my Sigma 70-200 F/2.8 OS out..I know it isnt a prime, but the IQ of it is nearly prime quality(for daytime atleast).

But, the Canon 200L (F/2.8 version) for ~$500-600 used is a BRILLIANT lens at a very decent price! And way faster, and imho, better than most "cheap" ED scopes.
And you have the added benefit of being able to use it for daytime photography..






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