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Old 07-10-2013, 12:36 PM
kosh
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2" T-Adaptors

Hi all,

Just wondering if anyone can tell me whether I would benefit at all by using
a 2" T-Adaptor over the 1.25" T-Adaptor that came with my scope.
I plan on using my canon 450D through a SW ED80 for DSO astro-imaging.

Cheers.
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  #2  
Old 07-10-2013, 02:10 PM
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RobF (Rob)
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2" will produce a LOT less vignetting - that's the standard most people use
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Old 07-10-2013, 02:40 PM
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mithrandir (Andrew)
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A standard 2" T-adaptor works with minimal vingetting for crop frame cameras. For a full frame a CNC Ultrawide should be better as it is a one piece device and does not have the 1.5" restriction caused by the threaded section. I've just ordered one.
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Old 07-10-2013, 03:06 PM
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doppler (Rick)
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I have a 450D (crop frame sensor) and a 102mm f7 achro and have had no vignetting problems with the 1.25" adaptor. I think that it is more of a problem with full frame sensors.
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Old 07-10-2013, 03:23 PM
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mithrandir (Andrew)
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Quote:
Originally Posted by doppler View Post
I have a 450D (crop frame sensor) and a 102mm f7 achro and have had no vignetting problems with the 1.25" adaptor. I think that it is more of a problem with full frame sensors.
It also depends on the f-ratio. Faster scopes are more likely to vingette.
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Old 07-10-2013, 07:09 PM
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acropolite (Phil)
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The SW reducer flattener is a worthwhile addition to the ED80 with the associated wide T ring there's no vignetting on FF should you upgrade in the future.
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Old 08-10-2013, 12:02 AM
kosh
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Thanks for your replies everyone.
I'm going to have to see if I have any issues when I actually get to use the scope for imaging, seeing as it's been cloudy every night since I got it. I was going to order a variable projection adaptor, thought I might get the larger t-adaptor and save shipping while I'm at it.
I think my scope is an f7.5. That's medium fast isn't it?
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