embedded data into dng, possible corruption percentage

[thomas]

hi everybody , im new and glad to be on board.  im concerned about the possibility of my raw files becoming corrupt by embedding iptc data. i prefer embedding the data to the file itself rather than just having it live in the dam program. my workflow is going to be adjusting , and adding keywords and other text to my cr2 files then converting them to dng, i dont know how common it is for a raw file to become corrupt by embedding metadata, nor do i know in which way and when it becomes corrupt, any light on this issue and how to possibly safeguard myself against it if possible would be great

[Michael_S]

Thomas,
Welcome to a fun corner of the internet.

As to your question/concern, I think most applications will not allow you to hurt yourself like you propose.  Writing metadata into an undocumented raw format like Canon's could be extrmemly bad.  Even resuliting in raw file corruption.

iView media Pro 3 won't write metadata into a Canon raw.  Canon won't document for 3rd as to where to put such information.  If you tried it in Adobe Bridge you would either be populating the Camera Raw database or writing a "sidecar" .XMP file (depending on your Camera Raw settings).  Adobe won't write into a proprietary camera raw file (e.g., CR2, NEF, etc.).  Ont he other hand, iView claims the ability to write into Nikon raw (NEF), Kodak raw, and of course, DNG.

If you use Bridge for these writes, I suppose you should consider sidecar files for use before you convert to DNG.  Or convert to DNG very early in your workflow so the DNG files can take the metadata directly internal to the actual DNG image file.  No database required.

Maybe you should convert to DNG very early on in your process, archive off the proprietary raws (CR2), and keep working with your "new" source file DNGs?
I hope this helps a little bit.

[peterkrogh]

Thomas,
The strongest way to protect yourself is to archive the RAW file as soon as you can, so that it has been touched by as few applications ass possible.  Remember that you should have multiple copies of anything you want to keep.

That said, here's what I do.  I edit in Bridge (using sidecar files to hold my data) and then convert to DNG in the DNG converter.  I then archive these DNG files as soon as possible.  This is a very safe way to archive the DNG files, since only Adobe software has touched them.

I'm not aware of third-party metadata corrupting DNG files so that they cannot be opened, but there is some discussion on this list of third-party metadata corrupting the file info as read by Bridge. I think it has been taken care of.

That said, I only push metadata back into the file because there is a reason to, and that is not a particularly common occurrence for me. Most of the info I need to put into a file is done in bulk metadata in Bridge.

Peter

[Joe Reifer]

Hi Peter -

I am on the verge of converting to a DNG workflow. As an iView user who shoots Canon digital, I was planning to do my metadata work in iView and use Sync Annotations to embed this info into the DNG.

Sounds like if I'm paranoid about file integrity, it might be better to add bulk metadata in Bridge, convert to DNG, backup the DNGs, and then catalog in iView without syncing annotations to maintain file integrity?

In this workflow scenario, what happens when:
 - I add caption or licensing information in iView for client delivery? [Convert to TIFF for client delivery & sync to TIFFs]
 - Prepare derivative jpegs for web use [Sync annotations to the JPGs]
 - Migrate from iView to other software in the future? [At this point I'd have to sync to the DNGs anyways]

Perhaps syncing to the primary copy of the DNG but not the backup copy is the answer? This could get confusing.

Your thoughts?

Thanks,

Joe

[peterkrogh]

Joe,
I think you are right on the money.  As outlined in the book, bring through Bridge, bulk annotate, adjust, convert to DNG.  Bring into iView and further annotate as necessary.  When you sync back, only do to the primary archive and only when necessary.  If you can have iView make a peel-off from a file, it can get the catalog's annotations without even pushing them back into the file.

I keep the backups as pristine as possible, and don't push data back into them (any change increases the possibility of file corruption).  Since the catalog data is more efficiently backed up by backing up the catalog, I find no compelling reason to push the data into the backups.

That said, pushing metadata into DNG files should be a very safe operation since the format is openly documented.

Generally, not confusing at all, IMO.  Push metadata back into the file when there is a reason, always make sure you have a backup, think about using the DNG converter to confirm file integrity.
Peter