[PRejto (Peter)]

Hi Terry,

I certainly have the potential to go fully automated with my gear but find there always seem to be adjustments here and there that need to be taken care of manually. And the ONAG in its present configuration without a motorized stage is just one of those things. Now, if it were possible to stick a larger CCD on the guider port I think that objection would become a non-issue. That's an expensive solution but not impossible if one had an older camera around that was gathering dust. Consider, though, that without the ONAG you need to invest in a rotator and that the OAG will have an even smaller FOV and more difficuty finding a star. I think a motorized stage or a large FOV guide camera would make the ONAG an ideal solution.

There are other considerations that need to figure in such as the back focus needed in order to use the ONAG. My refractors have enough available as do most SCTs. But, I don't think it's a viable solution if you want to use a fast system as available BF really shrinks. Then you need to figure out how to use a focal reducer in conjunction. After much research and head scratching I could not find any solution that allowed the FR to sit in front of the ONAG. The total optical length was just a bit too long no matter what brand I looked at. So, the FR would need to go after the ONAG. This introduces even further BF. It isn't a problem for me and I have done this with an Astrophysics barlow and have a FR if I want to try in the future. There also is a FR available for just the guide camera if you want both cameras to see the same field. These devices (balows, FRs) require that the guide camera also move back from the ONAG, but that is easy to do with the supplied tubes.

Just to complete this discussion, light pollution filters pose an additional issue to consider because they must go after the ONAG otherwise the IR frequencies are blocked from entering the ONAG. I had more head scratching moments figuring out camera mounting + LP filter on the ONAG. Mostly this was due to the smaller ONAG terminating in t-threads and I needed to use a 2" Hutech filter with threads only on one end of the filter. It has forced me to use a clamping system on the camera nosepiece which is not ideal. Recently I am incorporating the LP filter into the filter wheel in place of the "L' filter. There is always something to figure out...

Peter