Hi, Ok, I managed to compile and run the basecurve calculation program. The basecurve I get looks very similar to default canon curve. The colors look a bit closer to what I expect. Still a certain blue tone turns to purple while other blue tones stay blue. I wonder if there is another solution, e.g. by changing color zones.
Thanks for your help so far! Gerd On 16.01.2016 14:46, johannes hanika wrote: > hi, > > that example image is totally not dark saturated enough blue to > trigger the Lab conversion turns purple colourspace problem (which is > solved by the gamut clipping, as roman mentioned). i suppose you could > try to measure a basecurve from a CR2/jpg pair for that camera [0], > that affects colour saturation a lot, too. > > cheers, > jo > > [0] https://github.com/darktable-org/darktable/tree/master/tools/basecurve > > On Sat, Jan 16, 2016 at 10:24 AM, gersch...@gmail.com > <gersch...@gmail.com> wrote: >> On 09.01.2016 09:21, Roman Lebedev wrote: >>> On Sat, Jan 9, 2016 at 1:49 AM, gersch...@gmail.com <gersch...@gmail.com> >>> wrote: >>>>>>>>> blue colors in the raw files of my Canon 700D are turned into much >>>>>>>>> darker blue or purple >>>>>>>>> in darktable when applying the usual corrections (sharpen, >>>>>>>>> orientation, base curve). The >>>>>>>>> jpg files produced by the camera show a blue which is much closer to >>>>>>>>> the real color. >>>>>>>>> Is this a known problem? What Is the best way to correct this? I have >>>>>>>>> the impression >>>> that >>>>>>>>> this does not occur in rawtherapee. >>>>>>>> >>>>>>>> Yeah, this problem has been present for quite some time. I see it in >>>>>>>> shots taken with >>>> my Canon 60D >>>>>>>> but not in those taken with my 5d3. It's cased by the input color >>>>>>>> profile; try >>>> changing the profile >>>>>>>> from "enhanced color matrix" to "standard color matrix" or even >>>>>>>> "rec2020". >>>>>>>> >>>>>>>> The ultimate solution is to profile your camera using a color target: >>>>>>>> >>>>>>>> https://encrypted.pcode.nl/blog/2010/06/28/darktable-camera-color-profiling/ >>>>>>>> >>>>>>>> Darktable used to accept these custom profiles for inclusion in the >>>>>>>> main project, but >>>> this is >>>>>>>> currently not happening pending a rework on the way the input end of >>>>>>>> the pipe works >>>> (though I don't >>>>>>>> remember the details). None of this stops you using your own custom >>>>>>>> profile, though. >>>>>>> >>>>>> >>>>>> Thanks for your information. I've tested different input color profiles >>>>>> but I still have >>>>>> the impression the blue is too saturated. >>>>>> Is there someone with a Canon camera who would share their optimised >>>>>> color profile or >>>>>> darktable style? >>>>> Have you already tried setting "gamut clipping" in "input color >>>>> profile" to "linear Rec2020 RGB"? >>>> >>>>> https://www.darktable.org/usermanual/ch03s04s03.html.php#d0e7524 >>>> >>>>>> Thanks also for the hint to try RawStudio profiles. >>>> >>>>>> Regards, Gerd >>>>> Roman >>>> >>>> Hi, >>>> yes, I tried Rec2020 RGB with gamut clipping but now all colors look >>>> rather pale. I think >>>> that the colors in the standard color matrix look good except the blue >>>> being too dark. >>> Just to be sure: i meant: in "input color profile" module, set "gamut >>> clipping" to "linear Rec2020 RGB". >>> Not: in "input color profile" module, set "profile" to "linear Rec2020 >>> RGB". >>> >>>> Regards, Gerd >>> Roman. >> >> Hi, >> >> I've actually found a photo where the blue color situation of Canon raw >> files can be seen >> very well: >> Have a look at >> https://www.dropbox.com/s/8ikzw34pcvpstqf/IMG_7993.CR2?dl=0 >> https://www.dropbox.com/s/ykhmyu12c9o89sa/IMG_7993.JPG?dl=0 >> >> The real color of the shirt is very close to the blue in the JPG but it >> appears to be >> purple in the raw image if the standard base curve is applied. The setting >> suggested by >> Roman improves the color a bit but not enough. >> >> Regards, Gerd >> >> >> >> >> ------------------------------------------------------------------------------ >> Site24x7 APM Insight: Get Deep Visibility into Application Performance >> APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month >> Monitor end-to-end web transactions and take corrective actions now >> Troubleshoot faster and improve end-user experience. Signup Now! >> http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 >> _______________________________________________ >> Darktable-users mailing list >> Darktable-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/darktable-users ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Darktable-users mailing list Darktable-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-users
