If "Allow RAW modification" is off, does that mean completely off?

[Alan W. Smith]

I'm running Photo Mechanic 4.6.6 on Mac OS X 10.6.7.

After doing some research in the forum on how to setup Photo Mechanic to mark changes in the XMP files and leave RAW files unmodified, I found notes pointing to the Preferences -> Files -> "Allow RAW files (non DNG) to be modified for metadata and image preferences updates" switch. After unchecking it, the ratings I've done in Photo Mechanic only altered the XMP file as expected. I'm assuming this means that PM won't make changes to the RAW files at all, but would like to verify. So, my question:

Does having the "Allow RAW files (non DNG) to be modified..." flag in an unchecked state mean that Photo Mechanic will never alter RAW (non DNG) files, or are there operations that might still change them?

Thanks,
-Alan

[Kirk Baker]

Alan,

After doing some research in the forum on how to setup Photo Mechanic to mark changes in the XMP files and leave RAW files unmodified, I found notes pointing to the Preferences -> Files -> "Allow RAW files (non DNG) to be modified for metadata and image preferences updates" switch. After unchecking it, the ratings I've done in Photo Mechanic only altered the XMP file as expected. I'm assuming this means that PM won't make changes to the RAW files at all, but would like to verify. So, my question:

Does having the "Allow RAW files (non DNG) to be modified..." flag in an unchecked state mean that Photo Mechanic will never alter RAW (non DNG) files, or are there operations that might still change them?

I believe that is true.  I think that possibly that the GPS features may still modify them, but I would have to check the source code. Also if a RAW file has been previously modified with metadata PM will continue to keep it up to date with any metadata changes you make because otherwise the metadata inside the file would get out of sync with the metadata in the sidecar file.

-Kirk

[Alan W. Smith]

Been doing a little more testing with it and it looks like there are some changes made the to file when doing an ingest. I ran exiftool (from the Perl module Image::ExifTool) on a raw copy of a file and then again after PM ingested it. The attached screenshot shows the diff between the two outputs. Given the preference setting, this is not what I would expect. Can a fix for that be added to the bug queue?

(P.S. if you see that there are three diff hits, the other two are just the file name and permissions reported by exiftool. I don't think they are legit diffs in the file itself.)

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[Kirk Baker]

Alan,

Been doing a little more testing with it and it looks like there are some changes made the to file when doing an ingest. I ran exiftool (from the Perl module Image::ExifTool) on a raw copy of a file and then again after PM ingested it. The attached screenshot shows the diff between the two outputs. Given the preference setting, this is not what I would expect. Can a fix for that be added to the bug queue?

(P.S. if you see that there are three diff hits, the other two are just the file name and permissions reported by exiftool. I don't think they are legit diffs in the file itself.)

Are the file sizes the same?

-Kirk

[Alan W. Smith]

Nope. The file size changed.

Original
size: 33,527,261

PM Ingested
size: 33,529,321


Not sure if it matters, but I'll also mention that the test file is a full size RAW .CR2 from a Canon 5D Mk II.

[Kirk Baker]

Alan,

Nope. The file size changed.

Original
size: 33,527,261

PM Ingested
size: 33,529,321


Not sure if it matters, but I'll also mention that the test file is a full size RAW .CR2 from a Canon 5D Mk II.

It appears that PM put its Image Preferences on the end of the file.  Could you please post a screen shot (JPEG please!!!) of your Files tab and IPTC/XMP tab of your Photo Mechanic Preferences dialog?

Thanks,

-Kirk

[Alan W. Smith]

Here ya go. I fiddled around with both of these while trying to figure this out, but couldn't seem to get it in way that left the RAW images alone.

Thanks,
-a

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[Alan W. Smith]

Just wanted to check in and see if preventing modification of the raw files (when requested) on ingest is something that'll be added to the fix list.

Thanks,
-a

[Kirk Baker]

Alan,

Just wanted to check in and see if preventing modification of the raw files (when requested) on ingest is something that'll be added to the fix list.

We're looking into it.  I'll report back when we have news.

-Kirk

[Alan W. Smith]

Much appreciated. And let me know if there is anything else I can do to help out.
-a

[Alan W. Smith]

In case anyone hits this post while researching RAW images, I want to point to the post Is there a way to prevent editing RAW files that have already been edited once as well.

The short version is that you can use the "Tools -> Revert TIFF-based RAW to original" option to restore RAW files back to their original/pre-ingestion state. Once that's done, if you turn off the "Preferences -> Files -> Allow RAW files (non DNG) to be modified for metadata and image preference updates" option and restart Photo Mechanic, your RAW files won't be touched and basic modifications will only be stored in XMP sidecar files.

(Note: This worked with my Canon 5D MKii CR2 files running Photo Mechanic 4.6.6 on Mac OS X 10.6.7. Test on your setup with backup files to make sure you see the same behavior.)

[dennis]

Nope. The file size changed.

Original
size: 33,527,261

PM Ingested
size: 33,529,321

Not sure if it matters, but I'll also mention that the test file is a full size RAW .CR2 from a Canon 5D Mk II.

Alan,

Well yes it did in fact matter.  For some reason our "plug-in" for Canon CR2 files wasn't checking the preferences regarding RAW file modification and was appending the 2060 bytes we have for our End-Of-File preferences when copying (or ingesting) files and updating preferences.  No other changes were being made to the RAW file so it is very doubtful this bug would have caused any problems with other software (since it was only data added to EOF).  Nevertheless, I've added the check in the CR2 plug-in and it should now behave correctly on the next build and keep your CR2 files untouched.

I had been testing this with Nikon NEF files (what I use primarily) and never saw a problem.  Only CR2 files were missing this preference check.

So thanks for mentioning this "little" detail. 

Regards,

--dennis

[Alan W. Smith]

Cool. (It always seems to be those little ones that get ya.) Glad the details helped and I'm looking forward to the next version.

Cheers,
-a