Another way to handle the scans is import them into darktable, then update the EXIF data in the database. There is a lua script to adjust or set time for an image or set of images called, appropriately enough, adjust_time. It's located at https://github.com/wpferguson/extra-dt-lua-scripts.
On Sun, Nov 15, 2020 at 10:10 AM Stéphane Gourichon < [email protected]> wrote: > Hi Greig, > > You basically want to replace some EXIF information present in the raw > file. > > A number of people (including me) would strongly avoid ever modifying a > raw file. These are full of dragons. First I would make a backup of the > raw files for fear or any change triggering some wrong checksum > somewhere and making other software (or the camera itself) refuse to do > anything with it, claiming corruption. If any software claims to be able > to perform changes, I would open a binary comparison of before/after to > check what is the actual change. And keep the original raw files in a > backup, indefinitely. > > > The situation is somehow similar to a more common one : camera clock was > off and you need right times in EXIF after the facts. The typical case > being: at some events (wedding, etc) several cameras were used, clock > mismatch as always by minutes hours or days, making a mess of timeline > order. Fortunately the case of adjusting time is somehow covered by > darktable, which copies EXIF DateTimeOriginal to the XMP sidecar, as XML > attribute of rdf:Description XML element like this : > exif:DateTimeOriginal="2020:11:11 09:54:44" . Changing this line in the > XMP while darktable is not running was enough for me to get correct > datetime in Darktable and exported EXIF data, yay! > > I checked the source code (current git master), and alas this is > specific to DateTimeOriginal, darktable current code does not consider > overriding EXIF metadata from the XMP file, other than DateTimeOriginal. > > Would your need happen to me, I would either just ignore the problem and > live with it, or modify darktable source code to save that data to XMP > and read it back, then offer a Pull Request to the darktable team. > > It may be possible to manually edit EXIF values in the database, but I'm > not sure this can even work, and furthermore the current design of the > database is fragile with respect to the locations of raw files. More > concretely, whenever the raw file is moved, or happen to be stored on an > external drive that is mounted at a different place, you would probably > lose your customization. With the XMP sidecar, darktable would load it > again in those cases. > > > Addendum: to handle comfortably the "several cameras with random time > offsets take pictures of same events over a time range" case, I wrote a > year ago a script to automatically adjust batches of pictures. It saved > the day several times for me and I am considering publishing it as > open-source. Anyone who reads this (even years after) please consider > telling me if you're interested. > > > -- Stéphane > > > > Le 15/11/2020 à 02.55, Andrew Greig a écrit : > > Hi All, > > > > I shot and developed a roll of B+W film, and I will scan it using my > > Canon EOS 5D iv with the EF 100mm f2.8 Macro lens. As I was shooting > > the roll of film I maintained a notebook where I wrote down the > > settings, what is the best way to substitute the info in the resulting > > .CR2 files with the info from my notes? I am really looking forward to > > loading these into Darktable/Negadoctor. > > > > Thanks > > Andrew Greig > > > ____________________________________________________________________________ > > > > > darktable user mailing list > > to unsubscribe send a mail to > > [email protected] > > > -- > Stéphane Gourichon > > > ____________________________________________________________________________ > darktable user mailing list > to unsubscribe send a mail to > [email protected] > > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to [email protected]
