08-14-2017, 09:20 PM
Thanks for reply. When it comes to digital photography I'm definitely a novice. Some of your feedback pertains to topics for which I have little or no knowledge. However, I am grateful for the feedback and while I still don't completely comprehend what is at play here it does point toward some topics that I need to learn a little more about.
With that said, I have now a bit more information to contribute to the discussion. First, is that the .jpg file produced by GIMP cannot be opened by DPP4. DPP4 says it is not a valid .jpg file. This is troubling because I had the idea that the one big advantage of .jpg is pretty reliable universal support. On the other hand I cannot vouch for the robustness of DPP4. Second when I use DPP4 to convert the raw file to a standard format, either the .jpg referenced above or an 8bit .tiff, that I can open in GIMP the appearance of all of these files/images, to my somewhat non-critical eye, is pretty much the same (i.e., as opposed to the pretty drastic deviations revealed in the samples referenced above).
Everything seems to suggest that the process of passing the image data through UFraw results in conversion that affects the appearance which at least in this case is pretty drastic. Your point about the camera sensors being capable of more than 8 bits of color depth which I assume would be reflected in the raw format is new to me but does seem to be significant. When combined with the knowledge that GIMP operates in 8bit mode only this means some kind of conversion is indeed necessary. I think it safe to say that my experiment for bypassing UFraw left this job to DPP4.
A bit more research has also caused me to discover that there is something called an ICC profile that varies from one device to another. It looks like, I haven't completed research as of yet, UFraw must be customized with appropriate profile information for the specific camera in question. I did not do any such thing but rather expected that this is something that metadata could handle. What I'm thinking now is that this need was satisfied by the DPP4 software which knows about my camera. Furthermore, if this is not something that can be magically handled with metadata then Picasa has to deal with the same issue. So it now looks like that while Picasa could display a picture from the raw file it does not really, genuinely, support raw files. It tricks one into thinking so.
There is nothing special about the photo I used for an example. It was taken pretty hastily by an admittedly novice photographer and the idea that the exposure is less than perfect is probable. Similarly, my interest in raw files is not because I'm such a sophisticated photographer that I need them but rather that I'm curious about the technology associated with digital graphics. They are doing what I wanted which is causing me to learn more about the subject.
Thanks again for that.
With that said, I have now a bit more information to contribute to the discussion. First, is that the .jpg file produced by GIMP cannot be opened by DPP4. DPP4 says it is not a valid .jpg file. This is troubling because I had the idea that the one big advantage of .jpg is pretty reliable universal support. On the other hand I cannot vouch for the robustness of DPP4. Second when I use DPP4 to convert the raw file to a standard format, either the .jpg referenced above or an 8bit .tiff, that I can open in GIMP the appearance of all of these files/images, to my somewhat non-critical eye, is pretty much the same (i.e., as opposed to the pretty drastic deviations revealed in the samples referenced above).
Everything seems to suggest that the process of passing the image data through UFraw results in conversion that affects the appearance which at least in this case is pretty drastic. Your point about the camera sensors being capable of more than 8 bits of color depth which I assume would be reflected in the raw format is new to me but does seem to be significant. When combined with the knowledge that GIMP operates in 8bit mode only this means some kind of conversion is indeed necessary. I think it safe to say that my experiment for bypassing UFraw left this job to DPP4.
A bit more research has also caused me to discover that there is something called an ICC profile that varies from one device to another. It looks like, I haven't completed research as of yet, UFraw must be customized with appropriate profile information for the specific camera in question. I did not do any such thing but rather expected that this is something that metadata could handle. What I'm thinking now is that this need was satisfied by the DPP4 software which knows about my camera. Furthermore, if this is not something that can be magically handled with metadata then Picasa has to deal with the same issue. So it now looks like that while Picasa could display a picture from the raw file it does not really, genuinely, support raw files. It tricks one into thinking so.
There is nothing special about the photo I used for an example. It was taken pretty hastily by an admittedly novice photographer and the idea that the exposure is less than perfect is probable. Similarly, my interest in raw files is not because I'm such a sophisticated photographer that I need them but rather that I'm curious about the technology associated with digital graphics. They are doing what I wanted which is causing me to learn more about the subject.
Thanks again for that.