On 2012-12-31 00:03, Jose Carlos Garcia Sogo wrote: > One post on behalf of Pascal de Bruijn Very much appreciated, thank you! > Hi, > > Time to get some confusion out of the way. > > A typical complete camera input profile consist of two things: curves > and an XYZ matrix. > > The default color processing of Darktable (and most other open source > raw converters) use the Adobe DNG D65 XYZ color matrix (camera > specific), but that means the curve is missing. Which we complement by > applying a mostly brand specific basecurve. Does this mean that if I were to create my own input profile based on a test chart and with the correct settings, I would be able to get (more or less) natural looking images without a base curve? > Other open source RAW converters complement the color matrix with a generic > gamma curve > (often 0.45 which is the inverse notation of 2.2). But UFRaw for > example adds a linearity option (0.10 by default) which actually > distorts that normal 2.2 gamma curve to increase contrast (read to > make it look good), and the end result is probably not dissimilar to > how our basecurves look, except that it's not tuned to a particular > brand. The problem with this approach is that it leaves you with a > discrepancy how the camera processes the RAW (most people seem to > expect images in a RAW converter to look similar to what the camera > generates). And there is no way to solve that without applying brand > specific curves. Fair enough! > So if you disable the basecurve in darktable it's completely expected > that a RAW files will look dull, since the data is still linear (at > least to the extent that the raw sensor data is linear to begin with) > then. I did not expect this. Again, if I do my own input profile (and do it correctly), would I not be able to do without the base profile? > The idea that any particular approach would be "better" than any other > is nonsense, and please do not spread the idea that it would be. It's > just a preference nothing more. I apoligize if it seemed that I wanted to advocated a certain approach. I honestly just want to understand what is going on. Of course I have my own personal preferences for how I want my images to be processed, but I certainly do not want to claim them to be the only way of doing things. Of course I will think my own approach is superior, but then again, I would not have picked it if I did not think so :) > The difference between the curves: > Basecurve in camera RGB (before colorin) > Tonecurve in Lab colorspace (after colorin) Right now I do not understand what you are saying, but it is late and I may have been drinking too much wine. If I have further questions, I will post them tomorrow... > This is made visible by turning off plugin grouping in darkroom mode, > which I've demonstrated time and time again in my screencasts, My apologies, I have not seen all screencasts. I will try to catch up tomorrow. > so you > can see the static order in which plugins are applied (bottom to top). > These plugins account for everything being done, not just > "corrections". Thank you very much for your intervention, I was hoping this thread would catch your attention somehow. It is much appreciated.
I feel like I still do not understand everything, but I will leave the rest for tomorrow. Again, thank you! Eckhart Pedersen ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnmore_123012 _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
