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DSLR attachment help


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Hello all,

I am hoping to get a SW 200p newtonian ( 2nd hand ) and I want to start getting into imaging after getting used to the telescope but I have heard its more tricky than with a refractor as a refractor has a large back focus. I saw that you can move the primary mirror up the tube? Does this affect normal viewing? Is there any other way to create more back focus? And is it worth investing in an dual speed focuser, getting this would it solve the problem?

Thanks in advance

Austen

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The answer is easy with a Skywatcher focusser as the inch and a quarter eyepiece attachment unscrews and your T-Ring for the camera screws straight onto that.

No messing around moving the position of the primary mirror or anything.

Dave

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The answer is easy with a Skywatcher focusser as the inch and a quarter eyepiece attachment unscrews and your T-Ring for the camera screws straight onto that.

No messing around moving the position of the primary mirror or anything.

Dave

is this still true for the older versions ( the blue one )

Thanks

Austen

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For old 200P :

If you use the t-ring on the focuser itself, the DSLR "should" focus.

It won't with the 2" adaptor and a t-ring to 2" nose piece.

For new 200P :

With the newer focuser's, both should focus.

The limitation you will have with the old focuser, is the inability to use a coma corrector or filters in the chain.

Your resolution as stated is to move the mirror, buy a low profile focuser (better option in my opinion) or use a Barlow (to move the focal point out from the focuser.)

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It was a while back and I never used a DSLR but using a webcam I found for some reason on the older SW R&P focuser's had more inward focus than the later crayford type. So as advised by others if you use the T thread on the 2"-1.25" adapter you "should" have plenty of inward travel. The older focuser's also used a 2" adapter that reduced the dimension of the focuser draw tube but also extends the draw tube by 30+mm so this "should" I guess give you sufficient outward focus also ??? I know I'm not really offering much advice here but I would give the original focuser a try before you consider buying new focuser's as there is not just the cost element to consider. Most R&P focuser were of a smaller diameter meaning that you may have to cut and drill the OTA to get a new crayford focuser to fit.

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thanks so much everyone for your advice. Sorry to ask another probably simple question but by my moving the mirror up would it affect just visual work on while using the telescope? And is a barlow lens worth considering? If so what one would you reccomend.

Thanks so much everyone

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