Corrupt NEF Files

I would be most grateful if any of you could help me in either of two ways:  1) identify if there's a way to repair damaged NEF files, and/or 2) determine an archiving strategy that will prevent future incidents.

I have a backup strategy where I have an additional internal drive that I back up to, then I back up to at least two off-site drives (I cycle them into rotation on a regular basis).  I've recently been going back over older trips/shoots from 4-10 years ago, and I've noticed several .NEF files (I now convert everything to DNG and I guess I never got around to converting those files) are readable (i.e., I can open them in Photoshop and Lightroom, and they will copy over, and Lightroom can even convert them to DNG), yet they appear corrupt when they open.  Lightroom will open the files (either original NEF or converted to DNG), they initially look fine, but when the preview completes a large portion of the image is black.  Then, when I go back and look at the thumbnails, a large portion of the image is either green or red, or some combination.

So, I don't know how this happened.  I'm concerned additional files could become affected, and I don't know how to prevent this from happening, or if the currently impacted files can even be restored.  All files and my complete system have been scanned for viruses.  I used to use AVG antivirus in past years, but since moving to Windows 7 a long time ago, and now Windows 10, I've since always used Windows Defender and get the updates from MS.  So, unless those programs didn't catch the virus, I don't believe that to be the cause.

In addition, I've checked all my backups and, just as those files copied over without any indication of a corrupt file, they copied just like the versions I have on my primary drive.  Thus, I don't have a perfect copy of those files to revert back to.  This is something else I'm concerned about, because there's nothing to catch the issue, I don't know how to prevent it from happening in the future.

Thank you for hanging in there this long and letting me explain the issues.  I would be most grateful for and welcome your feedback.

Kind regards,

Tony

TDeSanto wrote:I would be most grateful if any of you could help me in either of two ways:  1) identify if there's a way to repair damaged NEF files, and/or 2) determine an archiving strategy that will prevent future incidents.

One thing to try Tony is opening them with Nikon Capture NXD. Easily downloaded from the Nikon site. Worth a try at no cost.

If you decide to download Nikon software, like Nikon Capture NX-D you usually download Nikon View NXi and NX-D at the same time. Once both programs are downloaded try viewing the NEF files in each program separately. Hopefully the NEF files will be read by each of them. In NX-D you can concert the NEF files to Tiffs and then import the Tiffs to another program like Lightroom or Photoshop.

Here is the link to download the latest versions: https://downloadcenter.nikonimglib.com/ ... w/118.html
The software download should say something like "...ALLINALL...."
Follow the directions carefully to make sure you get both programs. When you install, each one will install separately. Just watch the installation screens.

Whenever I have come across corrupt NEF files, the first thing I do is to uninstall the program and reinstall it. That usually fixes the problem. Once I had corrupt NEF files that was due to a external hard drive that had become corrupted and all files on it no matter what the format were corrupt. I was saved by a second external hard drive that contained the same images.

Good luck.

Thank you both Don and Joe. Great suggestion on the Nikon software. I haven't tried Nikon View NXi, but I have tried NX-D. The images look the same in NX-D as they do in Photoshop and Lightroom. Strange, though, that every program can actually open the file and read it, but just cannot display it properly. I'm assuming that the initial view, for the first second or so, that looks normal is the embedded JPEG within the RAW file? Then, after every application I've tried finally renders the image, it looks corrupt.

I've never dealt with corrupt files that can still be opened by multiple applications. Usually a corrupt file, and maybe I'm using the wrong term here, is just that...corrupt and cannot be viewed or opened.

Here's what it looks like for the first 1/2 second, before it looks corrupt:
https://drive.google.com/open?id=1QW1jb ... mcL5FPlg19

Here's what it looks like in Nikon NX-D (screenshot):
https://drive.google.com/open?id=1GZzc0 ... ljPfEs-a3Z

Here's what it looks like in Photoshop (screenshot):
https://drive.google.com/open?id=1V9xMp ... M9RS43Sabz

Here's the actual RAW file:
https://drive.google.com/open?id=1tgcsw ... W5OSCsH3fU

There are a number of ways that files can become corrupt over time.  But the most common is human error.  If you unplug a drive without ejecting it, you are highly prone to FAT corruption which ends up looking like the files are corrupt as it basically modifies the table of contents for the drive.  When this happens, different fragments of the file get lost by the operating system since the entry in the table of contents (FAT) is incomplete.  Of course, over time, disks can develop bad sectors.

The reason the files initially look fine is because initially they open the embedded JPEG in the RAW file to give you a quick display but then it builds thumbnails based on the contents of the whole RAW file and if there is any corruption, that will then display.

The reasons your backups are corrupt is because backup programs look for changes in files.  A corrupt file has a different file size, different parity, etc so the program interprets that the file has been modified and updates the backup.

How to prevent it:
1) Never ever turn off, unplug or remove a drive from a computer without first ejecting it through the operating system.
2) Run disk diagnostics on a regular basis, say every three months, to allow the bad sectors to be copied to other places on the drive and mark the bad sectors as off limits.
3) Replace old drives after 5 years and copy all information to new drives

EJ,

Thank you very much for taking the time. Drives have always been internal; thus, I suspect bad sectors had developed at some point...then I copied the issues to the newer, larger drive I'm using now as the primary storage drive.

Sounds like I need to implement a rigorous process of running quarterly diagnostics on my drives to prevent future problems. But, it also sounds like the files I'm currently having problems with are now unrecoverable. Too bad, but hopefully I can prevent any future problems.

Thanks, again, all for the advice.

Tony

Your best bet is to extract the JPEG so you at least have that.  It will be a smaller file though.  Once you do that, make sure to save it as a TIF to prevent open/save degradation inherent to the JPEG format.

BTW, it can happen on internal drives if you have a power loss.  This is why computers should always be on a UPS.  That way you can do an orderly shut down which prevents FAT corruption if you do have a power loss.

Great suggestion. I'll looking into at least recovering the JPEG, since those still seem intact on all the files I've tried to view. And, yes, firm believer in having a UPS.