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SCT question

Started by SunSpot51, 03/30/2004 03:49AM
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Posted 03/30/2004 03:49AM Opening Post
Paul Maxson
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Join Date: Dec 2003

Location: Surprise AZ, US

Posts: 1623

Has anyone ever measured their images at prime focus on an F/10 SCT? I measured a few of my Jupiter images tonight and if K3CCD is correct, with my Toucam in place, my system is giving very close to F/9 at prime focus. That, of course, throws off all my other focal ratios with the barlows I use. Not sure if it's my imagination or what? Just curious...

Paul Maxson
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Paul Maxson
Moderator - CCD Imaging and Processing/Solar System
Celestron C14, Mewlon 250, Orion EON120, ASI120MM, Flea3.
http://www.sunspot51.com
Posted 03/31/2004 02:34AM #1
Gary Carter
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The mirror position is what is causing the effect you point out. You can effectivly "reverse" this by putting a spacer between the Barlow and the camera (i.e. a flip-mirror or filter wheel). You'll have to work out the math to figure out how this affects the overall scale.
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-Gary
    There is only one constant in our infinite universe; it is change.
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    Chairman, Southwest Region of the Astronomical League (SWRAL)
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