Is it possible to use xmp sidecar files with tif?

[Etnoy]

So I'm scanning film, and Silverfast Ai outputs huge 48-bit tif files. I have used PM for years together with Lightroom, and there all NEF raw files from my Nikon camera remain untouched by both applications, instead using the xmp sidecar file.

I like the xmp files, not only that they make the application not touch the raw files, but also that I can update the metadata for files without my backup program having to re-do the backup for a large file when a change was only made to a few bytes.

The 48-bit TIF files are roughly 400 megabytes each. I have the storage to keep them all backed up, however it is cumbersome to re-do all backups when I add more metadata at a later stage. Is it possible to make PM "not touch" the TIF files and instead store all the data in xmp? Would that even work in Lightroom, or Photoshop?

Thanks for a great program.

[Linwood]

I can't speak for PM, but Lightroom won't use XMP's for anything but raw.  TIFF has a defined format for embedded metadata, and so most programs including Lightroom insist on writing it into the TIFF if it is set up to write at all.

Now in LR you can set the option to NOT update the XMP files, which will also have it not update the TIFF file, and keep it only in the catalog and write it on exports.  That will keep you from changing the TIFF's and triggering new backups.

This is one reason I dislike DNG's, by the way - minor metadata changes (if written to disk) update the DNG and I back up 50 megabytes instead of 5K for a XMP.

[Etnoy]

Thanks for the insight. I guess I'll have to carefully plan my metadata changes.