Hallöchen! Louis Granboulan writes:
> [...] > > You can download a DNG sample at http://dl.free.fr/grImV4Y5M This seems to be mechanical vignetting. I admit that d'Angelo's polynomial may not work well for this. I know such an effect only from one lens (the Sony E PZ 16-50mm). But there, the dark corners are shifted out of the viewframe by un-distortion. This does not help for a tele zoom probably. Lensfun should work for all lenses, but this is really unusual. > The coefficients above work well on this picture (using darktable) > but not on the TIFF. [...] Is the colour space linear RGB? You might try "dcraw -g 1 1 -T -W <DNG>". > [...] > >> Lensfun has the <center> tag, see >> <http://lensfun.sourceforge.net/manual/el_lens.html>. But I >> don't accept it in the database unless I'm convinced that a >> certain lens model has the same de-centering with each lens >> sample. > > What I was describing is not a lens centring issue, it is a > consequence of the sensor displacement. [...] Granted, but Lensfun's <center> tag is only the relative shift between sensor and optical axis, no matter what the cause is. If the displacement is encoded into the RAW, the RAW converter might generate Lensfun parameters which contain this displacement. So, the code for taking the dispacement into account is existing but it is the task of the RAW converter to make use of it. Out of curiosity: What is the maximal value for sensor displacement? Tschö, Torsten. -- Torsten Bronger ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Lensfun-users mailing list Lensfun-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lensfun-users
