I've read that the MI-250 can be difficult to balance, and does not like perfect balance but performs better with a little bias to keep the gears engaged and avoid "bouncing." Since you aren't guiding, and the backlash issues that can cause are not an issue, it is possible there's an issue with gear...

That is a tracking issue and not the camera. What mount are you using? Are you guiding the mount? 90 seconds is more than enough time for a Periodic Error issue to show. However, this type of image is common when guiding and encountering a backlash issue. So knowing the mount and whether you are gui...

The Sony IMX071 is listed under the heading of "Not Backlit + Not Stacked" in the Wikipedia listing for Exmor.

I think the question is about the little flange at the base. I'd guess it's only 2mm or so thick.

To NPB, why the concern? Are you trying to use a focal reducer or a flattener and have a specific spacing you are trying for?

With the ASI128MC in short supply or out of stock and seemingly discontinued, the new ASI6200MC-Pro, due late Jan. 2020, and similarly priced, would be the option. It's pixels are smaller, but with 60MP to play with, binning would somewhat address the pixel size issue.

Another handy tip. Thanks!

Ah, I see. Cool. Thanks for the clarification, and the how-to.

That's excellent!

Does not having a focus lock screw after the mod affect performance at all? With my focus lock completely loosened it seems a little sloppy. I usually leave that screw loose enough to adjust focus, but with a bit of resistance.

Thanks!

What brand and model of coma corrector are you using? Does it have instructions? Generally, there should be a specification for the coma corrector that tells you how much spacing needs to be between the corrector and the image sensor. Then you need to assemble the various spacers and connectors to m...

That's very helpful. Thanks Katherine.