SX OAG and Atik EFW2 Filter Wheel

[jabberwock48]

I already have an SX OAG and at the moment just an OSC camera. I was thinking of buying a mono camera and filter wheel. The Atik EFW2 seems to have less issues than the SX version but the Atik OAG is rather deep so giving backfocus problems with focal reducers as well as specific problems using the Williams Optics Reducer/Flattener 4 which I have. Does anybody know if the fixing holes in the 2 OAGs are the same so that the SX OAG can be mated with the Atik EFW2 (Some chance I guess!)

I guess if it is possible, then the Atik383L would be the best bet for the camera - any views please?

[steppenwolf]

I have this exact system all up and working with a FR IV and SXVF-H9 CCD camera. The mountings are not compatible with one another so I engineered a very successful modification by machining out the front face of the EFW2 to take the small rear extension on the SX OAG and then drilling and tapping suitable holes to attach the two together.

For reference, the SXVF-H9 has 17.5mm of back-focus and attaches directly to the male 'T' on the rear of the EFW2.

Here's a couple of pictures:-

[jabberwock48]

Well, thanks for the remarkably quick reply. I have looked at my SX OAG and see what you mean about the rear projection. I guess there are 2 choices - remove this projection and loose the positive centering it gives or machine the front face of the Atik EFW2 as you have done and presumably loose the chance of connecting to it in any other fashion. Either way alas I do not have access to a lathe!

I have some complications in that I have 2 imaging scopes mounted together - a 5in APO with the WO FF4 and a 14in Meade ACF with a Optec Pyxis and Reducer.

I get good guiding results with the APO using a guidescope but really need an OAG for good results with the Meade. So I would need to remove the OAG when using the APO - why, because the inward focus is limited and while I could just focus with a CCD and filter wheel in place, I would not be able to with the extra backfocus of the OAG

Regards

John

[Gina]

I think I'll stick with a guide scope - far less hassle

[steppenwolf]

I get good guiding results with the APO using a guidescope but really need an OAG for good results with the Meade. So I would need to remove the OAG when using the APO - why, because the inward focus is limited and while I could just focus with a CCD and filter wheel in place, I would not be able to with the extra backfocus of the OAG

I think I'm reading this correctly - so, why not guide with the ACF/OAG when imaging with the APO?