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Orion Mini 50mm Guide Scope with a ST-4 or SG-4

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#1 Tony Pilato

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Posted 10 November 2013 - 09:12 AM

Is or has anyone used an Orion Mini 50mm Guide Scope or similar models with a ST-4 or SG-4? It does not look that sturdy and I am worried about flexure and focus. Any help would be appreciated.

#2 Nebhunter

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Posted 11 November 2013 - 06:23 PM

Tony - I did a reply in the Astrophotography group. I see no reason why it should not work with shorter lenses in 35mm to keep within the resolution of the film, as long as your G11 is well drift aligned.

Igor

#3 Chuck Hards

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Posted 12 November 2013 - 08:51 AM

Are you talking about the older, slide-focus model, or the more recent helical focusing model?

#4 Tony Pilato

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Posted 12 November 2013 - 02:55 PM

Igor and Chuck (AKA Carpal Tunnel),

Thanks for helping out.

First - I would like to guide a 35mm OM-1 with a 135mm lens with a #25 Filter and Hypered Techpan to make what I call a Po' Man's Schmidt for Wide Angle HII regions in the Milky Way. I am looking at 2 to 3 hours exposure. Mirror flop on my C-11 was not helping my tracking.

Second, the Model I was looking at is:

http://www.telescope...Guide-Scope/...

I was wondering if the orion 50mm Guide Scope could handle the ST-4 head weight of 8oz. (the Orion StarShoot AutoGuider weighs around 4 oz.).

So can this guide scope handle the extra weight and a possible 4.5 inch extension tube if I need back focus.

I just hunted around the myriad of boxes in my "Smoke House" and found a Losmandy Dovetail Type System for my Finderscope which has ring diameters of 65mm and the distamce between the rings is 65mm. So it looks like I may be able to use that if neccessary to help reduce Flexure if needed. (Ihave to get some new screws for them). I just wanted some experienced advice for use without the newly found Dovetail Assembly.

Hope this clears up where I am trying to go...

Thanks,

Tony

#5 Chuck Hards

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Posted 13 November 2013 - 09:06 AM

The bracket does use a front O-ring, so you may get some flexure there. I have the helical-focusing version and wouldn't worry about the ST-4 to guidescope interface with it. I think if you really snug down all three setscrews it should be pretty firmly mounted, but of course you can't beat a threaded connection to be sure of eliminating slop.

#6 Tony Pilato

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Posted 13 November 2013 - 09:46 AM

Thanks Chuck,

I put up a post yesterday about the William Optics 50mm CCD Imaging Guide Scope # M-G50. It looks a lot better, and I have found a Losmandy type dovetail mount with 2 rings attached that should provide an even better set-up than the Orion Mini 50mm Guide Scope for the price. What do you think?

Thanks,
Tony

#7 Chuck Hards

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Posted 13 November 2013 - 10:51 AM

What focal length are you planning on imaging at? I'd say, the longer the FL, the more solid the guiding setup should be. I really don't have any experience with the WO unit.

#8 Nebhunter

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Posted 13 November 2013 - 11:40 PM

That would be the helical model.

#9 Tony Pilato

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Posted 14 November 2013 - 07:17 PM

Thanks everyone!

Tony






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