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eyepiece to large for T-adapter

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#1 Heimhenge

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Posted 13 August 2017 - 11:12 AM

Greetings Fellow Stargazers,

 

Only my second post here. I have two newer eyepieces (Orion Sirius Plossl 32mm & 40mm) that are too large to fit into my standard 1.25" T-adapter. With the rubber grips these eyepieces are 42mm diameter, but the T-adapter will only take up to 35.5mm. I looked around online for a larger body T-adapter but couldn't find one. Wondering if this might work as a solution:

 

https://www.telescop...ce-adapter.html

 

I see how that's supposed to work ... I'd screw my Canon T-ring (and any required spacers) to this device, then just mount my DSLR as usual. The DSLR is an early model Canon 20D and the body weighs like 1.5 lb. What I'm wondering is if those 3 metal set screws that hold it to the eyepiece are beefy enough to hang my camera on w/o skewing the optical path?

 

Does anyone here have experience with this product? Or can anyone suggest a better solution? Thanks.

 

Dan Heim



#2 D_talley

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Posted 13 August 2017 - 11:49 AM

Why don't you go directly from Scope to Camera without the eyepiece?  These lenses are so wide I don't think you gain anything using them for eyepiece projection.



#3 Heimhenge

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Posted 13 August 2017 - 12:14 PM

Are you talking about doing this at prime focus? I'm not sure I could get enough magnification. I'm trying to fill the frame with an H-alpha image of the Sun.



#4 D_talley

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Posted 13 August 2017 - 12:42 PM

Ok, I see now. What scope?



#5 Heimhenge

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Posted 13 August 2017 - 01:07 PM

Takahashi FS-128. And I have to get the Coronado etalon diagonal somewhere into the optical path.

 

FYI, I've done H-alpha before with this scope using an older 26MM Plossl that fits the T-adapter, so I've got all the basics down. I just wanted a lower mag to allow for more tracking error. Was getting 40X with that Plossl and wanted to use my 32mm instead, but that one doesn't fit the T-adapter, hence my original question.

 

Prime focus would give me about 33X (which would work) but I still need to get that etalon in there somewhere.



#6 astro744

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Posted 13 August 2017 - 01:51 PM

Maybe model UT1 or UT2 from the same source would be better at it has six screws.

 

See https://www.telescop...ther-t-adapters

 

 

 

 



#7 Heimhenge

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Posted 13 August 2017 - 02:47 PM

Yeah, I looked at the UT1. 6 set screws definitely more solid than 3. Wasn't sure from the single image how it worked, but after thinking about it I now see it's just a "long" version of the one I originally asked about. I might give that a try for the price, thanks.




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