Recovering corrupted .nef files

Software
8

@Narayan As a fellow hobbyist, I hope I can help. See below.

Exiftool

A day ago I wrote a post on exiftool that you might find useful: [Solved] Fast raw to jpg? - #11 by afre. The largest embedded image is probably PreviewImage but follow the instructions to find out.


PhotoRec

PhotoRec and TestDisk are a powerful set of tools. They are not the easiest to use but I have recovered seemingly unrecoverable files and filesystems with them. When you first use PhotoRec, the results may be disappointing. Just tweak the settings and try again until you get a desired outcome.

Advice based on my personal experience:

  1. File loss and / or corruption: along the way, something went wrong. Maybe it had to do with the copying over, or maybe it had to do with the integrity of SD card or hard drive or their controllers… Looks like there were multiple points where something could have gone wrong.

  2. Start as close to where the files were generated as possible. That would be the SD card. Since it is relatively inexpensive to replace, don’t take another chance with it in the future. It might fail on you again.

  3. Make a disk image of the card in case it is faulty (or file / folder image if you are dealing with individual folders / files). That way you can use an app like PhotoRec, which can wear the card even more, without worrying about it dying completely.

    Edit: please note that this image must be written to a separate hardware storage device, otherwise this precaution won’t work. Also, consider generating an image that is a bit-by-bit copy. It is a much slower and resource heavy process but it is worth it for apps that can take advantage of that.

  4. Do multiple searches with the same and different settings.

  5. Depending on your settings, the file type you are looking for, and how corrupt or old (overwritten) the files are; you might get files that are unnamed or have a funny name. Files can also have missing metadata, as you described above, or they may be missing information (partial images). You may find traces of very old files if they weren’t overwritten enough to disappear completely.

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