On Fri, Mar 3, 2017 at 6:58 PM, Chris Siebenmann <[email protected]> wrote: >> I recently purchased a Canon EOS 80D, I am a Debian (8.7) user. All this >> is quite new to me so it might be a newbie question rather than a >> problem with Darktable. Sorry beforehand if that is the case. >> >> TL;DR: http://imgur.com/a/eEipd >> >> When importing photos (CR2) into Darktable (2.0.7), >> colors/contrast/brightness... aren't the same as in the "Gnome Document >> Viewer" preview (and on the screen of my 80D). > > What I suspect is happening here is that the version of the image that > the Gnome Document Viewer preview and the 80D are showing you comes from > a 'preview' JPEG that is embedded into the RAW file (most RAW files have > several preview JPEGs in them at various sizes). This preview JPEG has > had all of the camera-specific magic processing applied to it, including > any in-camera styles you either set yourself or that Canon applies by > default. Also, even the embedded preview JPEG may differ, because different programs handle color management differently. I.e. some may not use display ICC at all.
> The darktable picture seems to be from the darkroom, where darktable > is processing the RAW itself from scratch. This from-scratch processing > almost never exactly duplicates the camera's own processing (partly > because camera makers never tell anyone what the in-camera stuff is > actually doing), and is sometimes not at all similar to it depending on > what settings the camera and darktable have. Generally the further from > 'basic neutral' you have the camera on, the more divergence there is > going to be. > > (Note that most cameras don't come set to 'basic neutral' out of the > box; usually their default picture setting is more cranked up than that, > because it looks nicer on the back of the screen and when people just use > the JPEG defaults.) > This is an issue in any RAW processor (apart from the ones from the > camera companies themselves), That is not really an issue :) > because none of them know exactly what > the in-camera processing is doing. Some RAW processors devote more > engineering and development effort to closely matching the straight > out-of-camera processing than others do, and so will come closer to the > look of those JPEGs by default. My impression is that darktable chooses > to focus development efforts elsewhere, so it winds up not necessarily > very close for many cameras and many camera styles. > (There are ways to get it closer in some areas if you want to do > some hand work. There are darktable tools that take some RAWs and > some corresponding JPEGs and work out much of the intensity/contrast > mapping between them to create a custom 'base curve' for the camera and > style. However cameras also often add things like colour shifts and > various sorts of sharpening and so on, and those are generally not going > to be duplicated through the base curve's mapping of intensities.) Also see https://www.darktable.org/2016/05/colour-manipulation-with-the-colour-checker-lut-module/ > - cks Roman. > ____________________________________________________________________________ > darktable user mailing list > to unsubscribe send a mail to [email protected] > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to [email protected]
