Nikon D800 NEFs ==> SubIFD Tags corrupted ==> Rewrite possible?

[williamwalsh]

Hi Phil!

I was trying to use your software but noticed that Nikon d4s nefs are not supported.

Images we shot from our wedding seem to be corrupted.

Thank you!

William

[Phil Harvey]

Hi William,

If they were corrupted by Nikon software, then send me one of the files and I'll see if it is possible to fix with this utility.  If so, then I will require more samples shot at various compression settings to be able to add support.  My mail is philharvey66 at gmail.com

- Phil

[williamwalsh]

Hi Phil,

Thanks for your response. I'm sending you the file via wetransfer.

We had been working with Nikon applications. If that's not the problem would you have recommendations?

Best,

William

[Phil Harvey]

Hi William,

I got the image, but it isn't the type of problem that is fixed by the fix_corrupted_nef utility.  To me, the file data looks OK, but it seems that the raw data is at least partially corrupted.  However, the good news is that the full-sized JPEG images may be recovered using ExifTool with this command:

exiftool -w %d%f_preview.jpg -jpgfromraw -b DIR

- Phil

[williamwalsh]

Wow! Thanks Phil. The Jpegs are extracting perfectly!

Do you see anyway that the Raw data could be recovered? Also, have you heard of Adobe Lightroom or Adobe Bridge corrupting files?

The first time that we experienced corruption is when we opened these files in Bridge and Lightroom.

Thanks a million,

William

[williamwalsh]

Hi Phil,

Actually I'm noticing that many of my nefs in multiple folders across multiple drives have this corruption. Can corruption spread like a virus? I'm sorry if I'm bugging you with this... I've just never seen corruption happen like this.

Best,
William

[Phil Harvey]

Hi William,

I haven't heard of NEF corruption due to Adobe software.  Nikon software is another story, but I haven't seen corruption like this from any software -- only due to disk problems, but apparently this isn't your situation.  Are the modification timestamps on the files recent?  If so, what software touched the files?  Also, do you have any antivirus software which could have potentially interfered with the writing of these files?

I doubt that it would be possible to recover 100% of the raw data.  Recovering more than you see now may be possible, but would probably be some work.

- Phil

[williamwalsh]

Hi Phil,

We don't have any anti-virus software. We work on a Macpro and a Macbookpro.

The short of it is that we purchased a G-tech 4tb Raid Drive to use a central working drive. We upload our photo work to it and about 3 months in the drive started having issue mounting and ejecting. We send it in the manufactor and received a refurbished replacement.

It was when we started using this replacement drive that we started noticing the corruption of Nefs.

Since then, we've received 3 hard drives from HGST and each time the folders and files from the original drive are uploaded the drive starts performing strangely.

We're not sure how many files are corrupted, as there are a lot of volumes to search though and we've been concerned about spreading any issues, but so far it only seems to be Nefs across multiple folders.

Best,

William

[williamwalsh]

The corruption is really wide spread. Effecting Jpegs, Psd, nefs, etc.

It almost seems like the corruption worsens when I preview the files.

[williamwalsh]

To add on to my last comment:

I'm also really confused because the files that are on my newest replacement are corrupted, where as the same files from the drive I transferred them from appear to be intact.

[Phil Harvey]

This sounds very scary.  I hope you can isolate this problem.

- Phil

[williamwalsh]

Hi Phil,

Yeah, it's really scary. Thanks for the help!

Blessings,

William

[drjazz]

Hi Phil -

is there a chance that you update this program to work on D5 NEFs...?
I didn't use ViewNX2 software but Windows Teracopy with a new (never used before) CompactFlash Card adapter - I ended up with a 200+ mutilated NEFs. I can display them - they have color streaks and pixel shift - and they can even be converted to DNG. However the DNG shows the same errors...
Would your software work wonder...?

Thank you very much!
Regards
Ueli

[Phil Harvey]

Hi Ueli,

If you send me one of the corrupted images I'll take a look to see what can be done.   My email is philharvey66 at gmail.com

- Phil

[Phil Harvey]

Hi Ueli,

I got the files you sent.  As you said, there is some corruption of the raw data.  The metadata is almost completely intact, but unfortunately there are also some problems in the data for the preview images.  These NEF files store 4 embedded images:

Size	Type	Tag
5568x3712	JPEG	JpgFromRaw
1620x1080	JPEG	OtherImage
640x424	JPEG	PreviewImage
160x120	TIFF	ThumbnailTIFF

You can use the following command to extract all of these:

exiftool -preview:all -b -W %d%f_%t%c.%s DIR

Unfortunately there is some corruption of the larger embedded images (JpgFromRaw and OtherImage) in the files you sent.  The smaller images (PreviewImage and ThumbnailTIFF) seem intact.

I know of no way to easily recover from minor bit errors like this.  The best I can suggest is to try to extract the embedded images from all of your NEF's, and if you are lucky maybe some of the large ones are still intact.

- Phil