On Monday, 7 January 2019 15:49:55 CET Jim Robinson wrote: > I am trying to determine the vignetting corrections for a new lens (Laowa > 7.5mm F2.0 MFT) using using the lens_calibrate.py program and images taken > through a translucent sheet. I appreciate that with a very wide angle lens > like this it might overestimate the vignetting, but that is not the > problem. I run the program and get the lensfun.xml file which I then add > to the lensfun database (there is already an entry there for this lens for > chromatic abberation and distortion). If I then use darktable to apply this > correction to either the .pbm or .pgm files produced by lens_calibrate the > correction is very good (as it is for a 16bit tiff exported directly from > the demosaiced raw without any other processing) However if I apply it to > the original raw file (Olympus .orf) the correction is very poor with only > about half the degree of correction required being made (though it does > seem to be consistently out by proportionally the same amount). Thinking > this might be a darktable problem I then tried rawtherapee and ufraw, but > they both had the same problem with the raw file. Does anyone have any > ideas what might be going on, or has anyone seen anything similar? > Obviously I will raise this with darktable developers (my preferred > application), but given that rawtherapee and and ufraw behave in the same > way there may be a generic problem.
I think there is a bug in the script. Roman pointed out that the input color space of the XMP used needs to set set input color space too. I will update the XMP file and fix it. I will let you know once I have done that. _______________________________________________ Lensfun-users mailing list Lensfun-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lensfun-users
