I don't know the answer to your question, but you might examine a LR-TIFF and a PS-TIFF before manipulating in Cumulus using EXIFTool and see what it shows as being different.
BTW, I don't understand why you'd want to convert all your JPGs to TIFF, because the process would not remove the original JPG-compression artifacts. If you continue to manipulate the images in PS or LR then saving as TIFF once manipulated would be ok, of course, to keep from getting any more artifacts, but not just something to do to all your images.
Thanks for the link I'll check it out.
"BTW, I don't understand why you'd want to convert all your JPGs to TIFF"
It was part of a process of making our archive fall within guidelines laid out by
the Library of Congress.
Okay, using exiftool I took snapshots of the same photo's metadata in 4 different states.
1- I took a tiff created in Photoshop and wrote keywords to it from Cumulus.
2- I then imported that photo into Lightroom and exported a tiff copy.
3- I reimported The PS tiff into Cumulus and added a keyword so we could
see specifically where Cumulus writes.
4- I brought the LR-tiff back into LR, added a keyword, saved to the file and
then imported that into Cumulus. I added a keyword in Cumulus, saved to
the file and, pow, all the IPTC data is gone.
So, there are only a few thousand that we have written keywords to from Lightroom.
I will stop that practice and only write from Cumulus but, I still wonder if I should convert
all of those tiffs to PS tiffs. hmm...
If you have changed metadata in a file outside of LR you will need to read this into the LR database by either synchronising the folder the files are in or using the update meta data. Note this will over write any meta data in LR. If you want metadata written in LR to be in the file itself as well as in the database, you will need to write to the file. You can set preferences to do this automatically. When you export a new file from LR you can select whether to write all the metadata or minimise metadata (which writes only the copyright information ) in the export dialog.
A TIFF is a TIFF, matters not which application made them.
"A TIFF is a TIFF, matters not which application made them."
This is very untrue. Just from using Exiftool to look at the metadata of a PS TIFF and a LR TIFF it is very obvious that they are different. The issue I am having is that, if I write metadata to a TIFF using LR and then write to it using Cumulus all of the IPTC data gets stripped. This does not happen if I modify metadata using PS. My question was if anyone knew what specifically differs in the metadata section between a LR TIFF and a PS TIFF so I can forward that info to the Cumulus engineers.