After reorganizing my image collection I moved a bunch of photos between different hard drives. While copying, I did get error messages. Fortunately, I had made multiple copies before doing the reorganization, so I was able to create my new image collection.

But since I got error message while copying, I'm getting nervous and would really like to verify the integrity of my library, i.e. check that all raw files exists, and that none of them has become corrupted.

Is there a way to check this? Or a tool that can check raw files for corruption? (In my case, Canon raw files, the images are taken with 500D and 7D cameras)

My image collection are split between a Lightroom catalog and an Aperture catalog. The latter uses referenced images, i.e. all the raw files are not stored inside the catalog.

  • \$\begingroup\$ So just to be clear, you want to check the integrity of your RAWs and catalogs ? Or just your RAWs? \$\endgroup\$
    – Olivier
    Commented Nov 20, 2016 at 13:10
  • \$\begingroup\$ Related: photo.stackexchange.com/questions/46919/… \$\endgroup\$
    – Olivier
    Commented Nov 20, 2016 at 13:12

1 Answer 1


short answer : use a third party file management software with checksum

Two operations to check your RAW files integrity have been mentioned in a related question (Is there a tool to check the file integrity of a series of images?):

  • regenerating the JPG preview
  • exporting them as DNG

However, as most of the data in a RAW file is in some binary format to save space, you probably can generate an image from a corrupted file with no warning. Only your eyes will tell that something isn't right.

As classical RAW files (Canon's CR2 and Nikon's NEF for example) do not have an embedded checksum, you can't use a native function of those formats.

The DNG format has a built-in checksum. Converting all your images into DNG is an option but it may not be the ultimate solution : Is switching to DNG worthwhile?, Do I lose anything converting to DNG?. You can also look at this article "DNG vs RAW" : https://photographylife.com/dng-vs-raw

I would recommend using a third party file management software supporting the creation and use of a checksum database. After a quick research, the free software ExactFile (http://www.exactfile.com) might be what you are looking for (I have no affiliation with this program). One of his features is "making sure files haven’t been changed or damaged over time".

Of course, this software won't help you if your RAWs have already been corrupted.


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