Hello! I appreciate this has come up before, but after scouring the forum I still don’t understand how I can rectify it myself.
Darktable 3.6 on Windows 10, camera is Olympus E-M10 Mark IV.
I can see that darktable recognises the camera but when selecting the body in the lens correction dropdown it isn’t there. It doesn’t feel right choosing a Mark III, I’m unsure if there’s much difference but I crave consistency!
I’ve been through lensfun and found the xml files containing all the lenses and the corresponding directory in darktable, but the issue is the camera body not the lens, and I have no idea where the camera info lies within lensfun, or how to update it on a PC.
Any assistance would be gratefully and cheerfully received!
Went looking through my lensfun db, sure 'nuf, the Mark IV wasn’t there. But, I then checked my db version, it was out of date. After updating it, it’s there.
That said, what’s important is that there’s a camera model entry with the correct crop factor for the lens. @Peter’s advice in the above post addresses your problem in that way.
Slightly off-topic, but I just ran in to a somewhat related problem. This past weekend, I put my FX 70-300 on my DX Nikon D7000 and got some nice train shots. Came home to process, and discovered lensfun wouldn’t apply corrections. My problem is that the lensfun corrections are for a crop factor of 1, and the camera is a crop factor 1.53. To correct that, someone (me, probably) would need to collecte the data for that crop combination. I mention it here for others who are debugging “why lensfun won’t work for me” problems - it’s not sufficient to just have a lensfun entry for a lens, it also has to have entries to support the required camera crop factor. May be intuitively obvious to some, but for the rest of us gomers…
I wasn’t aware that the cameras were listed in mil-olympus.xml, and I subsequently found that I wasn’t able to edit that file in the program folder… But opening notepad as administrator and navigating to mil-olympus.xml I was able to enter the Mark IV data and save.
And Glenn I appreciate your reply, I wasn’t sure if selecting a similar camera as a workaround would cause any processing errors, but I understand the only information being used there is the crop factor which wouldn’t have been too big a deal. In any case it works now in an automatic, joined-up fashion and is very satisfying.
