Resolved SG-3 Short /AC4040 FOV

Hi, I have an SG-3short and AC4040. I need to build an accurate FOV in TheSkyX for the system. I have a placeholder setup that is correct for the main AC4040 imaging chip, and has the correct SC-3 chip, but I do not know how far from the main chip the SG-3 chip is. In the past I've used trial and error when building an FOV for an off-axis guider, but I thought I'd ask here if anyone has one built already? I realize that where in the light path you have the pick-off mirror affects this, but a starting point that someone else uses won't hurt. If I don't get an answer, I'll post mine for what it is worth after I figure it out. Currently, my inputs for the SBIG ACt4040 and SC-3Short are:

SC-3: size x-axis 6.2mm y-axis 5.0mm
offset x-axis 0 y-axis 26.0mm
Element 3 circle diameter: 47.25mm
Element 4 circle diameter: 57.25mm

Element 3 and 4, and the y-axis offset for the SC-3 are the ones that I do not know at this point. The numbers I am using create an FOV shown in the attached document.

Thanks,
Mark

 

Thanks Doug, I'll grab the moon when it is next around conveniently!

 

Hi Colin, I have done that in the past, although I recall having some difficulty in getting a good plate solve on the guider chip. I'll give that a try tonight as the Moon seems to not be around right now. It is always in the way when we don't want it, and I guess never here when we do.

 

I point my scope at a large open cluster such as M35 or M11 to get a good plate solve on my guide chip, that usually works for me.

 

Hi, the crescent moon helped me find the right side, and then some trial and error with the moon and then stars resulted in a successful FOV creation in TheSkyX. In case it helps anyone else, attached is a montage of TheSkyX fov screens showing the inputs used for my setup. This may be of some help. Also include a pic of the camera so you can see how the SC-3 is oriented with respect to the AC4040 (necessary to get the side correct).
Best,
Mark