I just got myself a Samyang 14mm lens, more precisely the Samyang 14mm f/2.8 AE ED AS IF UMC, branded as Walimex Pro, but that is basically just a sticker, the lens is the same. In its latest incarnation with AE, so there is no more manual aperture setting and the resulting images contain Exif data. Nice. However, Samyang decided to label the lens Canon EF 14mm f/2.8L II USM in the Exif data, so automatic lens correction doesn’t work. With this small Lua script that can be fixed by just replacing the lens name on import. I just have to make sure to never buy the real Canon lens as that would be “fixed”, too.

local dt = require "darktable"

dt.register_event("post-import-image",
  function (event, image)
    if image.exif_lens == "Canon EF 14mm f/2.8L II USM" then
      image.exif_lens = "Samyang 14mm f/2.8 AE ED AS IF UMC"
    end
  end
)