Yes, I did so for a Tamron Zoom before it appeared in the database with a matching name. But it is annoying to repeatedly do this after updates of the involved tools.
I’m not a dt programmmer, so I don’t know how exactly the program is acting to achive the matching lens. Using exiftool I get the following entries for a Sony macro lens regarding the lens :
[EXIF] 0xa432 Lens Info : 50mm f/2.8 [EXIF] 0xa434 Lens Model : 50mm F2.8 Macro [MakerNotes] 0xb027 Lens Type : Minolta/Sony AF 50mm F2.8 Macro (D) or F3.5 [MakerNotes] 0xb02a Lens Spec : Unknown (00 0 0 0 0 00) [MakerNotes] 0x0603 Lens Format : Full-frame [MakerNotes] 0x0604 Lens Mount : A-mount [MakerNotes] 0x0608 Lens Type : Minolta/Sony AF 50mm F2.8 Macro (D) or F3.5 [MakerNotes] 0x0105 Lens Mount : A-mount [MakerNotes] 0x0106 Lens Format : Full-frame [MakerNotes] 0x0109 Lens Type : Minolta/Sony AF 50mm F2.8 Macro (D) or F3.5 [MakerNotes] 0x0115 Lens Spec Features : Macro [Composite] - Lens ID : Minolta/Sony AF 50mm F2.8 Macro (D)
It would be very interesting for me to know which tag is used for identification. I guess it is the Composite tag “Lens ID”. Possibly a dt coder could give some insight or just point to the source code where identification is implemented. The dt manual only says : “darktable finds this data in your image’s Exif information”.
Update: did an intens search and found darktable/master/src/common/exif.cc. As far as I understand mainly tags of type “LensModel” are used, by different handling for different manufacturers. Special treatment of Sony SAL lenses where aditionally the tag “LensID” is used.
After I saw this code I have compassion for the programmers and great respect handling this mess of information being provided by the manufacturers in a very inconsistent way.