DSLR Focusing problem with new focuser

[nathkrul]

Hi Guys an Gals, (dam, sounds like jimmy savile)

Here is my problem, I have a skywatcher 200p scope with the old rack an pinion focuser which reaches focus ok with my canon 40d. So I bought a crayford focuser the skywatcher type, upon taking the old r&p focuser off I noticed a BIG problem it won't fit without serious modification, so I decided to get the dremel out and enlarge the hole, redrill it and I made a lovely job of it, a perfect fit.

Soo I looked outside, goddam the sky was clear, sets everything up, aligned to stars, attaches camera, guess what can't acheive focus its too far away,( slaps head ) packs everything up.

So I've been looking at this low profile focuser on First light optics

http://www.firstlightoptics.com/proddetail.php?prod=sw_low-profile_focuser

Will this be ok as its more low profile than the skywatcher focuser.

Thanks

Colin

[blinky]

Have you any idea how near to reachine focus it is? I would assume it's not too far since it worked with the R&P one. I would hazard a guess and say it would fit, I think the focuser yo mention will be manufactured to allow a DSLR to come to focus in a newt.

Dont hold me to that though....

[beamer3.6m]

I could reach focus with my 400d on the 200p with the skywatcher crayford.

How are you connecting the camera to the focuser?

[nathkrul]

Hi, I connect the camera using the canon adapter direct to the camera adapter thread on the focuser by removing the 1.25 eyepeice which is as close you can get.

On the old R&P focuser I had about 4 mm left before it would bottom out, with the new focuser I would need to go closer by about 3 mm because it is a lot thicker, also while searching the forum I noticed that other people have had the same problem.

The old R&P camera adapter plate is 8.5mm and the new adapter plate is 14.6mm so you can see the problem. And the old adapter plate is a different size thread so I cant use it in place of the other.

Thanks

Colin

[beamer3.6m]

Thats strange as I have the same scope and the same attachment set up but focus is reached I can only assume it is because I have a 400d and you have the 40d.

Its very frustrating when you cannot reach focus. I had it on my C80ED but this was out focus so I solved it with an extension tube.

I am not sure how to solve your problem, maybe give Steve at FLO a call.

[brendant]

The lens mount to sensor distance is the same on all Canon cameras, it must be for lenses to be interchangeable, difference in camera model is not the problem. HTH

Brendan

[MikeP]

If you only need a few millimetres, could you re-collimate in a slightly different position i.e. with the primary a bit further up the tube? The adjustments available in my FlexTube collimation bolts/springs would certainly allow me to do that.

Mike

[nathkrul]

Thanks for the replies everyone, I have been in touch with Steve and hopefully I'll have a fully working system again, going to try a low profile focuser.

Thanks

Colin