08-13-2017, 10:47 PM
The secret is, AFAIK there is no absolute accuracy (after all, you can still underexpose or overexpose your picture). Gimp/Picasa rendering is an image which on the average is pretty close to 40% gray, and this is what I get with pictures from my camera that I find correctly exposed. Your picture is 64% grays and is a bit washed out: light areas lack detail, like the stern of the sailboat and the clouds in the back.
DPP may be using proprietary information in the picture metadata, while UFRaw and Picasa don't. If you want an accurate rendering, then use a color chart and shoot it in at least one picture of the series. Then correct colors in UFRaw so that the chart is accurately rendered, save the settings, and apply them on the other pictures.
However, the purpose of raw images is to let you take advantage of the full dynamics of your sensor to extract the most data from the shot. Remember that Gimp is only 8-bit, while your camera sensor is 12 or 14 bits. The raw converter works in 16-bit (or even 32-bit), so there is very little color loss when you do general color/level/contrast processing in it, unlike Gimp where Color tools will induce rapid color loss. You have to make choices and decide woith of the 14-bits are going to be squeezed into the final 8 bits. This is work (IMHO, a good 10 minutes on the simpler cases...) and is a matter of "artistic" interpretation. If you just use the defaults there is absolutely no point in using raw, you can just as well use the JPEG from the camera. By the same token since you are supposed to spend so much time in the raw conversion process you can just as well save that result. And at that point, little difference between going to Gimp directly or switching applications and explicitly loading that file. And if you do so you are no longer limited to the more Gimp-friendly applications, there are plenty of free and powerful raw converters (for instance RawTherapee and Photozone...).
DPP may be using proprietary information in the picture metadata, while UFRaw and Picasa don't. If you want an accurate rendering, then use a color chart and shoot it in at least one picture of the series. Then correct colors in UFRaw so that the chart is accurately rendered, save the settings, and apply them on the other pictures.
However, the purpose of raw images is to let you take advantage of the full dynamics of your sensor to extract the most data from the shot. Remember that Gimp is only 8-bit, while your camera sensor is 12 or 14 bits. The raw converter works in 16-bit (or even 32-bit), so there is very little color loss when you do general color/level/contrast processing in it, unlike Gimp where Color tools will induce rapid color loss. You have to make choices and decide woith of the 14-bits are going to be squeezed into the final 8 bits. This is work (IMHO, a good 10 minutes on the simpler cases...) and is a matter of "artistic" interpretation. If you just use the defaults there is absolutely no point in using raw, you can just as well use the JPEG from the camera. By the same token since you are supposed to spend so much time in the raw conversion process you can just as well save that result. And at that point, little difference between going to Gimp directly or switching applications and explicitly loading that file. And if you do so you are no longer limited to the more Gimp-friendly applications, there are plenty of free and powerful raw converters (for instance RawTherapee and Photozone...).