Does anyone know if it is possible to write all the necessary information, notes and keywords in a DNG without any problems? So far, as I said, I’ve been doing this and haven’t noticed any problems.
DNG is not in itself a raw format, and it is (on paper) an open standard (*). So it is possible for third-party programs to modify a dng reliably. That said, it is impossible to know if all programs writing to dngs implement the specification correctly… But “non-raw” dngs are usually derived from another file, so even if there is a corruption, you should be able to go back to the original file…
I would still be very reluctant to modify a raw dng (one directly produced by the camera), but that is to minimise the risk of losing the original.
So far, I’ve not had any serious problems with sidecars. But when using several programs modifying them, some care is required.
The formats of raw file formats are not “officially” documented, especially not the makernote sections. Often, location of a piece of data is specified as an offset from another piece. That’s where the problems start: miscalculate the offset, and bad things happen. It doesn’t help that there are a lot of variations in the makernote section (digikam has a list of makernote fields you can chose to display, the number of sections in that list is rather large…)
Hello @rvietor
Your thoughts don’t really encourage simply writing to the raw files, even those converted to dng.
If I understand you and the thoughts of others correctly, then it would make more sense not to write anything in the raw files. In other words, to work with the sidecars after all.
I’m thinking about whether it’s better for me to sacrifice convenience but be on the safe side.
I remember from Windows times when I managed my photos with ThumbsPlus and whenever I wrote keywords in the Fuji raf, all the settings and the date of the raw files were broken. At first I thought the camera had a problem. DigiKam has never broken anything - and I want to keep it that way.
Not quite.
Personally, I will not write to raw files. For me, that would include camera-produced dng files.
But writing to dng’s derived from a raw file is different: those have a well-defined format, and you still have the original raw file. So there’s no risk of losing the image when writing to the dng file, which is the important point.
How beautiful!
I’ve been converting all my raw to dng with Adobe DNG converter for the last few years and digiKam could put anything I wanted in there. That was great. Since I deleted all the original raw afterwards, I now also have concerns. I don’t want to keep them in parallel either. The effort would be too great.
DigiKam recommends not deleting the originals in any case. What do you think about this?
NEVER delete your original raws.
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Thank you, those are clear words, I will take them to heart.
I have often regretted that myself!
As to keywords, I don’t mess with them in apps. I enter them from an hierarchical list using XnView MP which has the best exif/iptc/xmp search engine on the planet. My pictures are scattered here and yon on my hard drive and they will stay so scattered until I die.