Williams Optics Star71 & Atik Imaging Setup

[alexjj67]

I think I know the answer to this but I hope I'm wrong

I would like to get the Star 71. But I am concerned by the 55mm back focus.

I have a 383l+ with a BF of 17mm + EFW2 BF 22mm + OAG BF 24mm equalling 63mm.

Does this mean I wouldn't be able to achieve focus with this setup?

I could loose the OAG and go to a guide scope. But I'd prefer not to. 

Or is there any other scopes of the quality and around the price with a Back Focus of more that 63mm.

Cheers 
Alex

[martin_h]

http://www.williamoptics.com/telescopes/images/WO-STAR%2071%20BACK%20FOCUS(20141029).pdf

[StevieO]

Hi,

I have a similar set up, shown below. I don't use an OAG, though. I fitted a SW finder shoe to the scope and use a standard 9 x 50 finder with an Orion Starshoot autoguider, which gives me good results. The filterwheel is an SX. This setup achieves focus after winding out the focuser to about 17mm.  So it looks like the additional 24mm of your OAG may prevent getting focus as you say.

Hope you find a solution, the Star71 is a fantastic scope.

Regards

StevieO

[r3i]

I run an SVX-H9 + filter wheel + OAG with the Star71.  I'm not sure how much length this all adds up to but there was still a bit of focus travel left. 

[alexjj67]

Cheers Guys