Hello, I missed this very important message for the original topic of distortion.
As you may have guessed, Siril developers don’t know much about the things that seem to be obvious to most folks around here, having to do with digital camera picture management.
I’ll start from the beginning then, and to quote you will help:
As much as we do not handle distortion in Siril, we do not add any either. We only use the raw data from the sensor, if the stars end up square or very elongated, it’s because the optics create a geometrical aberration off-centre. I understand you expect something to happen in the software to correct this, I wouldn’t even know how this works personally, but how did you “test the lens specifically for distortion”?
I’m sorry that your (and many others here) experience with Siril is a failure in the most part. I don’t know if we will be able to improve this, I hope we do at some point, at least by providing a gateway to software that does things as you expect…
For reference, the continuation of the colour management discussion happens here: Color management in Siril, need help and refactoring.