Author Topic: Missing metadata, could PM be the cause?  (Read 320 times)

Offline Paul StL

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Missing metadata, could PM be the cause?
« on: January 04, 2019, 10:21:17 AM »
I use Chronosync to keep four hard drives (one working at home, one working at work, & 2 backups) of photographs synced.  My drives are organized by year/event and to make Chronosync faster, I usually create a new Chronosync document for each year.  I hadn't done drive-wide syncs in a long time so a few days ago I decided to do full drive syncs.  Surprisingly I discovered that a group of photos (NEFs) from May/June 2016 were conflicting with the problem being different file sizes.  The get info command (Mac) showed image sizes of 0 x 0 and the color space and color profile were missing in the smaller version of the files so it appears some metadata is missing.  The size difference was usually about 12,800 bytes.

So here's where this may or may not be Photo Mechanic related.  The files were vacation photos from different time zones than I live.  On those vacations, I had borrowed a computer from a friend that had Photo Mechanic and had brought two of my drives with me.  The photos were copied daily to the hard drives from the memory cards.  I used PM on the trips to cull, crop and keyword the photos.  This, of course, would not affect/write to the NEFs directly.  However, when I got home, I copied the images from the memory cards to the other two drives and when I ran Chronosync, it came up with a time difference (two drives showed a time difference from the other two drives).  I presumed it had to do with the time zone differences between where they were taken and/or written so I used PM to fix the creation and modification times on two of the drives which would write to the NEFs.

So here's the question, is it possible that PM corrupted the metadata when writing to the files or is there another possibility/explanation?  Using PM on two drives but not the other two is the only difference in handling that I can think of.

Unfortunately I can't tell you the OS or exact PM version although I know it was v5.  The NEF files were from Nikon D7200 and D810.

Thanks and sorry for the long story (but needed to understand what happened).

Offline Kirk Baker

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Re: Missing metadata, could PM be the cause?
« Reply #1 on: January 04, 2019, 11:03:31 AM »
It is certainly in the realm of possibility that PM modified your files in an unwanted way.  Depending on IPTC/XMP settings, PM will embed metadata directly into NEF files (XMP and legacy IPTC metadata).  If your friend's PM was set to embed metadata in RAW files them PM would modify the NEFs if you made some sort of metadata change (captioning/tagging/rating/etc.)

The way the PM embeds the metadata allows it to be reverted to its original state (Tools->Revert TIFF-based RAW to original) so unless something extraordinary occurred while updating the file then nothing should be damaged.

-Kirk

Offline Paul StL

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Re: Missing metadata, could PM be the cause?
« Reply #2 on: January 04, 2019, 01:10:52 PM »
Thanks, Kirk.  I don't have immediate access to PM right now but if I can get a hold of my friend, I'll try reverting if for not other reason than to test it.  I've been wanting to buy PM for myself but Christmas time with five kids is probably not the time to budget it. ;D  BTW, nothing seems to be damaged as the files will open without any problems.  It was just disconcerting to discover.  (Maybe more disconcerting is that I haven't done a whole disk sync in apparently 2+ years).   :D