Date change on some files when changing exif rotation

[OldGrowth]

Hello,

I'm new to iMatch (just days) and still figuring out capability and workflow. I have about 275k images from a variety of sources. I have no DAM experience and am enjoying reading the documentation. As I reread I can begin to piece together the concepts and capabilities.

I used exif rotation to change the rotation of some images in my database. Afterward, I noticed some interesting behavior:

On images that were scans of negatives done by a lab over 15 years ago, which had only creation date and date/ time for exif data, those dates changed to today.

On images taken with a low quality cell phone camera, years ago (flip phone), where the exif dates were present and mostly correct, but the file name used an incorrect date in it, those dates changed to today.

On images that were taken with a good automatic digital camera, no date change seems to have occurred.

Q: Is a change in the date when using exif rotate expected behavior?

I have found all the images I rotated using filter.

Q: Is there a reasonable way to batch edit the exif dates to be what they were, for those that changed? I believe the only place that date exists now would be in a previous version of the file in my windows file history, which is live on another partition of the same drive.

Thank you community and developer for this forum!

OldGrowth

[Mario]

Hi, welcome to the community.

This is a common issue with files not having any usable EXIF date and time information.
In these cases IMatch falls back to filling the standard date values (See Metadata Panel, "Default layout") with the "Last modified on disk" timestamp reported by Windows.
And this of course changes when you modify the EXIF orientation info via the command.
See How IMatch uses Date and Time Information for details.

Solution: First set a XMP date and time (created, subject created) in the metadata panel. Then write back the file once.
This saves the timestamps to the file and IMatch does not longer have to fall back to the "last modified" timestamp.

If many of your files have no timestamps and you must rotate them, you can save some time in the future by setting the setting "Mark file as pending write-back" to yes in Edit menu > Preferences > Metadata 2.
By default IMatch does not mark files as modified when it fills the XMP timestamps from the file system time-stamps (by popular demand).
Hence no write-back and the EXIF orientation modification you perform updates the timestamps after the EXIF orientation has been updated.

You can also avoid all this by using a virtual transformation in IMatch. This also correct the orientation of the file and does not require changes to the EXIF data. But it is also not visible for other applications, so you need to decide what works best for you.

[OldGrowth]

Mario,

Thank you for your complete and clear explanation. I'm glad to understand what caused the perform, and now I can address the date issues with these files as well.

I like the ability to fix exif rotation in the iMatch interface while I do other work on my photos, so I'll use one of the tips you shared.

I was too busy to jump into this project of organizing my photos for quite awhile but have been interested in this software for over a year; I'd read that the community and your support are excellent, and certainly that's the case here. Much appreciated and thanks for the welcome.