I do own the “Canon EF 70-200 f/4L IS USM” lens for a long time now, and have been shooting it with at least 3 different cameras. However, sorting my images by lens for the first time in darktable today, I am observing something weird: The lens is available two times with different names:
The name with USM is used for photographs between December 2021 and today, while the name without USM is used between October 2013 (I probably got it back then) and today.
The same happens for another lens: The “Canon EF 24-105mm f/4L IS” which also has variants with and without “USM”, but with another introduction date for the new name.
It seems that the newer photograph are sorted into both categories while the older photos are only in the category without USM.
Any idea what’s going on here?