Is there a way to prevent editing RAW files that have already been edited once

[Alan W. Smith]

I've got a set of RAW files that were imported by Photo Mechanic where the app made changes to the files' metadata. I know that even if I turn of the "Allow RAW files (non DNG) to be modified for metadata and image preference updates" in the preferences, Photo Mechanic will still update the RAW files in order to keep that data in sync with the sidecar data.

I'm wondering if there is either:

1. A way to turn this off. Or,

2. A way to edit the RAW files (maybe by removing some PM metadata) that would prevent PM from further editing the RAW files and write changes only to the sidecar files. If that's possible, I could use something like exiftool hopefully remove the necessary data.

I'm pretty sure there isn't a way to turn it off, so I'm hoping file edits would get me there. I figured I'd check to see how PM determines it's going to make edits to RAW files before I go too far down the path.

The reason I'm after this is to prevent the RAW files that were ingested by PM from being further edited when I make rating changes to them.

(Running Photo Mechanic 4.6.6 on Mac OS X 10.6.7 with files from a Canon 5D MKii)

Thanks,
-a

[Kirk Baker]

Alan,

I've got a set of RAW files that were imported by Photo Mechanic where the app made changes to the files' metadata. I know that even if I turn of the "Allow RAW files (non DNG) to be modified for metadata and image preference updates" in the preferences, Photo Mechanic will still update the RAW files in order to keep that data in sync with the sidecar data.

I'm wondering if there is either:

1. A way to turn this off. Or,

2. A way to edit the RAW files (maybe by removing some PM metadata) that would prevent PM from further editing the RAW files and write changes only to the sidecar files. If that's possible, I could use something like exiftool hopefully remove the necessary data.

I'm pretty sure there isn't a way to turn it off, so I'm hoping file edits would get me there. I figured I'd check to see how PM determines it's going to make edits to RAW files before I go too far down the path.

The reason I'm after this is to prevent the RAW files that were ingested by PM from being further edited when I make rating changes to them.

There are two Tools that may be of use here.  One is 'Delete Metadata' and the other is 'Revert TIFF-based RAW to original'.  I suggest trying them each on a backup file and see what produces the best results.
Both commands are on the Tools menu.

-Kirk

[Alan W. Smith]

The 'Revert TIFF-based RAW to original' worked for me. As noted below, the only trick is that the 'Backup IPTC/XMP to XMP sidecar files" checkbox in the dialog must be checked/on for the reversion to work. (Not a problem for at all since getting that data stored only in the side car is what I'm after.)

After I ran the 'Revert TIFF-based RAW to original' and unchecked the "Preferences -> Files -> Allow RAW files (non DNG) to be modified for metadata and image preference updates" box to turn it off, I rated, flagged, set the color class and cropped an image all without altering the source RAW file. Exactly what I was looking for.

Thanks,
-a


P.S. A few notes from my testing for prosperity's sake:

* The 'Revert TIFF-based RAW to original' returns my Canon 5D MKii files to their original state (md5 hash == original file) if the 'Backup IPTC/XMP to XMP sidecar files" checkbox is checked/on. I tested this with the "Preferences -> Files -> Allow RAW files (non DNG) to be modified for metadata and image preference updates" both on and off. It worked fine in both cases.

* No change is made to the file if the 'Backup IPTC/XMP to XMP sidecar files" checkbox is unchecked/off, (md5 of ingested file does not change from before/after the reversion is done).

* The 'Delete Metedata' option also reverts the ingested file back to its original state (md5 hash == original file) if I run it with everything _except_ the "Exif" and "Tiff Artist" check boxes checked. (Note: I've got my rig setup to add my name in camera. This value goes into the artist field. Your millage may vary if that's not setup.) I tested this with the "Preferences -> Files -> Allow RAW files (non DNG) to be modified for metadata and image preference updates" both on and off. It worked fine in both cases.