Darktable 3.0 Exif on export

thank you,
Exif.Photo.FNumber=8 is working, but then I have change for every foto this metadata.
Is it possible to set a variable that reads out the information of aperture of the lens correction module?

my goal would be to readout the 3 infos of the lenscorrection module

  1. name: samyang 12mm
  2. f=11 (aperture)
  3. focal length=12mm

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