John,
One reason I picked the 27TVPH instead of the CCDT67 was the longer focal length (700mm vs 305mm) which provides a bit more room for an AO unit. If you haven't found it already, there's some technical info and example spacing calculations on the 27TVPH and CCDT67 here:
http://www.astro-physics.com/tech_su...r-techdata.pdf
My image train is: RC10, Atlas focuser, [optional 27TVPH], AO-LF, SX filter wheel, SX OAG, SX H18 camera.
My spacing between the FR and CCD focal plane is fine. My only concern is total back focus distance. I haven't proved I can reach focus with the FR and AO combined yet. It will be very close with my current set of off-the-shelf adapters. If I can't get there then I'm certain I will be able to with a custom adapter from 2.7" to 72mm which will replace three separate adapters between the FR and the AO unit. I just need a clear night to check my current configuration...
Cheers,
Rick.
Quote:
Originally Posted by JohnH
Rick,
I am curious - can you use the FR and AO unit together and still get the CCD spacing right? What is your imaging train exactly? I was not planning on the 27TPH - rather the CCDT67 as my ccd is smallish and will work with the greater FR that gives BUT I am not sure about spacing with a CFW8 and potentially, an AO-8, in line.
Regards,
John
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