I recently upgraded from Mac OS 10.28 to Mac OS 10.45 and had some interesting discoveries about RAW file integrity.
I have previously been using a workflow for Canon CR2 and CRW files that only includes iView Media Pro and Photoshop.
I read the DAM Book, and realized that looking at thumbnails in iView (with prefereces set to use the embedded preview instead of building a new one) does not
confirm the integrity of the actual file. Opening the folder of images in Bridge confirms the file integrity because it builds the preview from the original. A good way to identify any corrupted RAW files.
I am not converting to DNG yet, but have read the DNG converter is also a good way to confirm file integrity.
When I upgraded to OS 10.45, now the operating system can render previews of my RAW files. I recently embarked upon a project to make yet another backup of the files on my machine by moving them to a second external Firewire drive. When I went to copy the files to the external drive, not all of them would copy over. Apparently the Mac OS will error out if the files are corrupted. This happened both when I tried to just drag and drop files from my HD to the Firewire HD, and when using the SuperDuper! backup program.
Here's a couple of interesting discoveries. After identifying a few corrupted CR2 files, I tried running them through the DNG converter to see what would happen. The files converted to DNG with no error message, both from Adobe Camera RAW, and in the Adobe DNG converter.
OK - Are you still reading this? Sorry for being long winded. To review, here is where file integrity is confirmed in my current workflow:
1. Files transferred to computer, open the file folder and OS 10.45 will not show a preview for RAW files it cannot read.
2. Files copied to an external Firewire harddrive. Again, when moving the files, the OS checks integrity.
3. Files opened in Bridge, builds the preview from the original file, confirming integrity. I am not using Bridge until migrating to a DNG workflow - if I open my files in Bridge, and don't
convert to DNG, I am saddled with XMP sidecars, which I don't like.
4. Instead, I'm considering using iView with preferences set to render its thumbnails from the original file instead of the embedded preview. This will confirm file integrity, but of course take longer to import.
*Note: Again, I was able to run corrupted RAW files through the DNG converter without any errors. These were files where the preview in Bridge showed up, but the colors were all screwed up (maybe the camera was turned off when the file was still writing?). I have not tried the DNG converter on files that did not show a preview at all.
If you think this email is long, you should've hung out at my house last Saturday when it took me 10 hours to figure all this stuff out.