I have a wide angle shot that even after lens correction shows some distortion of the horizon. Is there a way to fix this in Darktable? Or should I take it out to Gimp for example for final corrections.
I could not find a proper module to further correct the ‘smiling’ horizon (barrel, pincushion correction)
Note: this is taken with a Canon 17-40 F/4 L USM lens using a Fringer EF-NZii adapter on a Nikon Z6iii. In the lens correction module I choose the Canon R6ii (also FF and 24mp) and the Canon 17-40 lens manually to get the correction working.
If you use this combo of equipment frequently, it might be worthwhile to do your own lens profile. Otherwise, you might find yourself fighting the same battle repeatedly. Check out these:
your problem is no problem, if you just respect the dunes on the left to be higher than the waterline. After rotating the pic a little bit, there is no “smiling” on the waterline at all (Lensfun under RT 5.12):
I can’t see anything wrong regarding distortion on the horizon. I just corrected a bit the falling lines, which could have been avoided when taking the photo, by holding the camera not that far to the sky.
