Viltrox/Lensfun problem

Software darktable
,
1

Hi,

I have a strange problem with darktable or lensfun. I have a Viltrox 16 mm lens, lens ID: “Viltrox AF 16/1.8 Z”. There is already this lens included in lensfun database, Sony version: “Viltrox 16mm F1.8 FE”. Even if I manipulate misc.xml to exactly match this string, darktable shows “unknown lens”. And correction does then not work.
The only workaround so far is to keep the original misc.xml and then manually select “Viltrox 16mm F1.8 FE”.
This matching however should work and I don’t know why it does not. Does anyone know?

2

Is it possible, that the available correction data is intended for a different crop factor, i.e. sensor size? This could lead to such effect.

3

Both have crop factor of 1.0.

4

Hm, OK. So might perhaps be a problem regarding the lens ID. I would suggest to do a search on “lensfun exiv2” in this forum, as there are quite some topics with respect to lens recognition issues. You may always override lensfun using an exiv2.ini (Windows) or .exiv2 (Linux) configuration file (there are also quite some topics covering that) as long as the the software has trouble to recognize the lens. So I assume, that this issue will be solvable.

5
1 Like
6 
exiv2 -pa --grep lens/i Z6B_1842.NEF 
Exif.Nikon3.LensType                         Byte        1  (0)
Exif.Nikon3.Lens                             Rational    4  16mm F1.8
Exif.Nikon3.LensFStops                       Undefined   4  0
Exif.NikonLd4.LensIDNumber                   Byte        1  0
Exif.NikonLd4.LensFStops                     Byte        1  F0.0
Exif.NikonLd4.LensID                         Short       1  2820
Exif.Photo.LensSpecification                 Rational    4  16mm F1.8
Exif.Photo.LensMake                          Ascii       6  
Exif.Photo.LensModel                         Ascii      65  Viltrox AF 16/1.8 Z
Exif.Photo.LensSerialNumber                  Ascii      11  0

At least with .exiv2:

[nikon]
2820=Viltrox 16mm F1.8 FE

It does not work.

7

Share the raw file and we can try to troubleshoot.