rg55
member
Reged: 08/02/08
Posts: 17
Loc: western US
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Can anyone share their experiences about flip mirrors and catadioptric telescopes for lunar/planetary phtography? Which work, which don't, etc.? Have a C8 and a 5" mak that I want to shoot through.
Thanks!
Richard
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C8 on AS-CG5 mount
Orion 127 mak
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Rusty
Postmaster
Reged: 08/06/03
Posts: 16396
Loc: Brooker, FL
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They all work, to some extent. Without some fiddling, none works to focus for AP; what they provide is an ability to see the general area the scope is pointed to. What they don't, again without some experimentation, is show the camera's field-of-view.
All-in-all, they're quite useful, given the limitations.
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N11GPS Fastar
TOA-130S
MK66 Std
Vintage C5
Megrez II 80mm ED Triplet APO
SolarMax 40
NJP Temma II
Sirius EQ-G
ST8XE/CFW-8(LRGBHa)/AO-7/DF-2/STV Dlx/ST237a/350D (Unmodded)/Mallincam Color Hyper Plus/DSI III Color/DSI II Pro
Two not-spoiled Golden Retrievers - Maggie and Casey
Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering. - Arthur C. Clarke
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Raven911
Pooh-Bah
Reged: 03/12/05
Posts: 1440
Loc: New Mexico
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I could get my flip mirror to focus with my 127mm M500 only at it's full focal length of F10. It worked decently enough for planetary AP, but was woefully inadequate for deep sky imaging since I could not get it to focus with a reducer in place.
Now, try it on a refractor and it does become a useful item.
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http://smg.photobucket.com/albums/v287/Raven911/Astrophotos/
http://www.eye-of-the-raven.blogspot.com/
Celestron SC6
IM M66 Mak-Newt
100mm F6/76mm F4.5/80mm F5/SV NHII 80mm F6 Achros
SBIG ST7/Canon 300D/DSI Pro Mono/Starshoot DSCI
8 inch F7 Newt on Edmund EQ
8 inch F4.5 Project Astrograph
Edited by Raven911 (08/04/08 12:33 AM)
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sang33ta
professor emeritus
Reged: 07/08/08
Posts: 539
Loc: UK
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Alternatives..
You could use a Heartman focuser (cheap) or what the pros use a Stiletto focuser. (costs!)
You could use an electronic focuser and some software to to talk to it.
You can also get prisms that split the light? Not sure.
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Hioptic 152mm f12.5 Maksutov
Celestron Advanced CG5-GT Mount (Mr Noisy!)
Meade 4000 Super Plossl Set
Casio QV-2900UX
Got fed up of waiting for Meade ETX-150 so put this together for £500/$1000 
Edited by sang33ta (08/04/08 12:19 PM)
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rmollise
Carpal Tunnel
Reged: 07/06/07
Posts: 1637
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Quote:
Can anyone share their experiences about flip s and catadioptric telescopes for lunar/planetary phtography? Which work, which don't, etc.? Have a C8 and a 5" mak that I want to shoot through.
I use a flip mirror with the C8 for all my planetary imaging. The basic Meade model I've got--don't need nuttin more expenisve--works fine. If your MCT focuses via a moving primary mirror, there shouldn't be any problems there, either.
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Uncle Rod
Watch for Rod's New Book:
Choosing and Using a New CAT--coming in December!
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rmollise
Carpal Tunnel
Reged: 07/06/07
Posts: 1637
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Quote:
Alternatives..
You could use a Heartman focuser (cheap) or what the pros use a Stiletto focuser. (costs!)
You could use an electronic focuser and some software to to talk to it.
You can also get prisms that split the light? Not sure.
None of these things help at all with the main problem that people have with planetary imaging: using a small chip camera, which most planetary imagers do, and running the scope at f/20 or f/30 means it is danged near impossible to get a planet in the frame with go-to or finders. You will hunt and hunt until you start deforesting your scalp. 
A flip mirror not only allows you to center a planet on a chip; it allows you to at least get close to focus.
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Uncle Rod
Watch for Rod's New Book:
Choosing and Using a New CAT--coming in December!
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rg55
member
Reged: 08/02/08
Posts: 17
Loc: western US
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Hi Rod,
Thanks for the info. Do you use the 644 or 647? I have a 2" visual back on my C8--is it a good idea to go with the 647, or...?
Richard
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C8 on AS-CG5 mount
Orion 127 mak
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rg55
member
Reged: 08/02/08
Posts: 17
Loc: western US
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I understand a little how the Hartmann mask works, but don't get the stilleto.
Do you use a motofocus, or recommend one?
Thanks, I'm learning a lot!
Richard
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C8 on AS-CG5 mount
Orion 127 mak
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rg55
member
Reged: 08/02/08
Posts: 17
Loc: western US
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Thanks, Rusty. It sounds like something to check out at a local star party first. Good information!
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C8 on AS-CG5 mount
Orion 127 mak
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rmollise
Carpal Tunnel
Reged: 07/06/07
Posts: 1637
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Quote:
Hi Rod,
Thanks for the info. Do you use the 644 or 647? I have a 2" visual back on my C8--is it a good idea to go with the 647, or...?
Richard
For planetary imaging, the 1.25-inch version is more than sufficient. Deep sky? Flip mirrors are practically useless for that unless you shoot at f/10.
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Uncle Rod
Watch for Rod's New Book:
Choosing and Using a New CAT--coming in December!
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rg55
member
Reged: 08/02/08
Posts: 17
Loc: western US
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Great. I appreciate all of the articles and posts you've done. I'll be learning for a long time, but it's great.
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C8 on AS-CG5 mount
Orion 127 mak
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