I read that in using shorter focal lengths, best results are obtained with 1x binning. I'm using a 10" RCA w/flattener (1725mm @ f/7) and STL-11k and full frames take a good bit of time to download. If I choose to bin at 2x to save time, will that savings cost me a significant loss in accuracy when real-time collimating?

In my case accuracy is key because my system really sensitive to showing astigmatism at the slightest miscollimation. According to CCDInspector, my collimation figure is about 3.0 and I still can see a little astigmatism in one corner. From that value being so low, it may be falling into the noise pit so I don't even know if CCDInspector can even help me beyond where I am now.

Hi Roth,

You can bin your chip, and still get reasonable results. If the seeing is particularly good that night, you may need to very slightly defocus your system when doing collimation to increase star size.

3 arcseconds for collimation is excellent, and I doubt you can improve that much on it. I'd look into whether you may have a slight image plane tilt, either in the focuser or in the camera attachment. If you'd like, email me or post an example of an image, and I'll take a look.

Regards,

-Paul