08-16-2017, 03:20 AM
(08-15-2017, 05:23 PM)Ofnuts Wrote: Yes, there are such things as "color profiles". But as far as I know (I own two Canon DSLRs) the Canon pictures use the sRGB format which is the default. In practice, you can tell your camera to produce both CR2 and JPEG. If you do so, you can compare the JPEG from the camera with the JPEG produced by from the CR2 by various applications. There is also the matter of the indicated white balance (but in your sample pictures, I think the problem is more an optimization of the global exposure).I did chase the profile matter today. The UFraw website was not much help. Broken links for just about all of the references. However, I was able to find a single .icm file within the DPP4 directories and this appears to be exactly what you describe. It was called "sRGB Color Space Profile (sRGB v1.31 (Canon) - Canon, Inc.)". I was able to add that to UFraw and it had a very minor/subtle effect on the appearance but enough to suggest that it was being used. This suggested to me that my issue is caused by something else.
As to DPP4 not supporting JPG from GIMP: when you export the JPG in Gimp, un-tick the "progressive JPEG" option in the advanced settings. If that fixes the problem, it means that DPP4 is not supporting something that has been part of the JPEG standard for about 15 years. For their defense, DDP4 is meant to process what comes form the camera and nothing else.
Another experiment involved using UFraw to see if I could manipulate the appearance to resemble what DPP4 was producing without doing anything. By using the exposure control only I can get very close if not right on. Using only my eyes to judge limits the extent of the match I would claim to have but since it is something conspicuous to my eyes which triggered this discussion I'd say we're onto something. Interestingly, when I open the raw file with UFraw the exposure control shows -.29. When I select the reset button it goes to zero. This suggests to me that UFraw did make an adjustment even though I hadn't requested any change. If I set the value to 1.0 the picture resembles what DPP4 is showing me without trying to change anything. At this point I have no idea what kind of adjustments DPP4 might be making without my knowledge.
The idea that UFraw or any other editing software can make simple adjustments that improve the appearance is what we're after but I want to know what is being changed. I've done enough study to know that camera's have a lot of exotic software that automatically performs some, if not a lot, of editing. That was my prime motive for being able to produce raw files was for me to be in control of such changes, which I'm expecting to help me learn how this stuff works. The idea of setting the camera to make both raw and jpeg files is something I also thought might help. My camera setting have already been changed but I have yet to take any pictures. I'm going to try and match the conditions in the example photo we've been discussing. Hopefully tomorrow.
I'll try the suggestion regarding GIMP export to jpeg and post results.