Inconsistent image size between dark and focusing images

Hello. I’ve recently got an electronic focuser and am trying to find reliable settings in KStars that also work in areas with only dim stars.

To avoid problems with hot pixels, I took darks in the Dark Library of the Capture module, with the same ISO and exposure time. I’m shooting with an Olympus E-M5 II, for which sensor temperature does not seem to be recorded.

Now when configuring the Focus module to use darks, it always says that it can’t find a matching dark. I’ve analysed the FITS headers of focusing frames and darks, and noted that while the dark reports to have a resolution of 4608 x 3456, the focusing frames have 4640 x 3472.

Doing some quick research, most online reviews/spec site report the 4608 x 3456, while dxomark reports 4640 x 3472. According to Claude, the latter is probably the physical resolution, but the camera might use the outer ones for dark current calibration and automatically apply a crop. However then how did the Focus module get the full resolution?

The Gphoto INDI driver was at first set to the 4608 x 3456 when I both took dark and ran the focus, both for the sensor size and the requested image size. I’ve since changed both to 4640 x 3472, but I cannot change the requested image size in the Capture module to 4608 x 3456. It allows 4608 x 3456 max. I also tried setting the format to native raw, which disables the image size controls, but I still get 4608 x 3456 darks.

So this might be the problem? I’m not sure where the Capture module gets this max size from, if I changed the values in the INDI driver to 4640 x 3472?

Note that I had also saved this config in INDI and confirmed that the config file only has the 4640 x 3472, and nowhere the formerly used 4608 x 3456.