I have a couple of questions related to this discussion, slightly off topic but I am stuck. I have been using an Edge HD 11/Hyperstar/ASI6200MM Pro/ASIAir Pro/50mm (200mm FL) Guide Scope with an ASI120MC-S Camera with great results for the past few weeks. This was my first setup moving from an ASI533MC to mono and I was really having a lot of fun with some fairly good pics (I posted some in my gallery). Guiding was working very well with an EQ6R Pro.
I reconfigured the Edge HD 11, removed the Hyperstar and installed an Edge HD .7 Reducer, along with a ZWO EFW and M68OAG. Starizona provided me with an adapter from the .7 reducer to the tilt adapter attached to the OAG. I purchased an ASI120MM-Mini to use with the OAG. The recommended 146mm of back focus from the .7 reducer to the ASI6200MM sensor is right on the money using the adapter that Starizona provided.
The first thing I noticed was that I was at the extreme infinity end of the focus travel (CCW) to get the main scope focused. It was a good focus but needed every bit of travel, as though the back focus needs to be reduced slightly. I can live with this situation.
The next problem has changed this hobby from being very enjoyable to miserable in two days. I cannot get the ASI120MM-Mini to focus through the OAG when attempting to calibrate/guide. I was able to get the guide camera and the main camera to focus in daylight on a mountain ridge 10 miles distant by forcing the ASI120MM-Mini all the way down into the helical focuser on the OAG with the Edge focus all the way to the CCW direction. When I finally get polar aligned and on target, I am unable to get the guide camera to provide any (virtually none) usable stars. I have tried various gains/exposures/focus settings on the guide camera with zero success.
If I remove the ASI120MM-Mini from the helical focuser and remove the HF from the OAG I can get somewhat of a focus on stars by carefully holding the camera almost against the OAG by hand. Even this does not produce small, sharp stars. Nothing that the ASIAir Pro can use to calibrate or guide.
I posted here because it sounds like several posters are successfully using the M68 OAG with the EFW and an ASI camera.
I am really out of tricks and do not have plan other than to call Starizona tomorrow. This is day two of all day with zero success.
What guide camera(s) are you guys using with the OAG? Any suggestions would be greatly appreciated.