Weird dark area in darks and biases, Panasonic M43 DSLR


Just getting my feet wet in astrophotography, and learning about bias, dark, flat and light frames. My light and flat frames don’t seem to be problematic, but I am getting strange artifacts when the RW2 bias and dark files that I capture with my mirrorless camera are opened and autostretched in Siril, a strange lighter coloured square in the centre.

Any suggestions?


This is exactly the same issue some Fuji users have:

However, your DSLR is not in our database and you should enter manually everything in the Siril preferences.

However, I need to check the code but I’m even not sure it works with Bayer pattern sensor yet.

As usual, without samples we cannot something.


I’ve tried entering the x- and y- information for the strange region, but it doesn’t seem to make any difference to the converted result. Here’s the RW2 file, if it helps:

This is funny, but the shape I got is totally different:

For sure, we can’t do anything with this kind of thing.