I don't *think* there is a way to make the .CR3 files match the .fits files. But it should be possible to re-shoot darks and make sure they are getting saved as .CR3 (easier than re-shooting the lights, for sure!).

You want to make sure you have your settings correct in the future anyway, so you are always working either in .CR3 or .fits. When I use my 700D, I always use .CR2 for everything so I can read the sensor temp in the exif header to match lights to my darks library.

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