Corrupted DNGs >:(

dex_ · Jun 27, 2017

A number of images I shot tonight were corrupted

. The facts:

Lightroom says "Lightroom has encountered problems reading this photo. You will not be able to make adjustments to the photo." Indeed, the Develop module just displays an error. I also can't Export any of them.
The Adobe DNG Converter tool says "There was an error parsing the file".
Lightroom can display lots of other metadata though (preview image, camera settings, GPS location).
I updated to the latest 01.03.900 firmware.
The corrupted images were all long exposures, from 0.6 to 4 seconds.
The corrupted images were mostly taken when I had a somewhat flaky connection, with a pretty low quality live feed. I got a number of "Strong inference" warnings, and lost RC connection a few times. (Seems like it shouldn't matter, since everything is stored locally?)

I'm pretty sure it's not my card or card reader or computer, because:

Other images I took earlier during the same flight are fine.
Images I've taken since (on the same card, not reformatted) are also fine.
I've reimported the files and have the same results.

Any ideas? This was pretty frustrating. I'll use RAW+jpeg in the future so I can at least salvage something if this happens again.

4wd · Jun 27, 2017

It could be a card problem, best to format the card in camera pretty much every time after downloading what you want.
RAW files are demanding on space and write speed - more so than 4K video

dex_ · Jun 27, 2017

Why would formatting help? Doesn't that just reset the filesystem?

Emmediemme · Jul 2, 2017

I have the same problem. Did you solved?

Calder2 · Jul 2, 2017

Same problem here. This has happened to me twice, both times at night doing long exposures.
Shutting the Mavic down while changing locations/between shoots and it's okay again.
The files are still large, so obviously there is something saved.

The irritating part is that you don't get a warning at all during flight, not until you get home and import the images into Lightroom. (I shoot RAW+JPEG, so I at least have a decent JPEG as a backup...)

*EDIT*
Was able to recover an image (have only tried it on one) with RawDigger, and could export it as TIFF. It however includes all hot pixels, but that can be fixed (manually at least).

dex_ · Jul 4, 2017

Thanks Calder2. Interesting that you also had an issue with nighttime long exposures. @Emmediemme: were your corrupted files also long exposures?

Interesting that you could open with RawDigger. I was able to open the corrupted files in Raw Therapee (open source raw developer), and I also had a bunch of hot pixels. Do you think that's a symptom of the corruption? Or do you think those are actual hot/stuck pixels that the Mavic normally fixes automatically somehow?

Meanwhile, @Miki said in this thread (Mavic DNG - LightRoom the file appears to be unsupported or damaged) that they were able to open the files in Photoshop ~~(I haven't that yet)~~. EDIT: I can't open my corrupted DNGs in Photoshop. Not too surprising, since they also failed to open in Adobe's DNG converter - presumably Adobe uses the same library in all their applications.

Calder2 · Jul 5, 2017

I'm actually too new to digital photography, but seeing it's only happened with long exposures, that's my theory so far.
I will send in a support request to DJI though, and see what they will say about it...

Meanwhile, I found a free program called HotPixels (HotPixels Eliminator), I ran the TIFF through (2-3 passes) and it removed all hot pixels. And a few warning lights on wind turbines in the distance... ;-)

Emmediemme · Jul 5, 2017

Yeah, all my DNG files are corrupted unfortunately.
I submitted two requests to DJI, one by mail and one by online chat. By chat they said me that it was a strange issue, and they would open a report sending the issue to their developers.

By mail I tried to send the DNG file so they can analyze that.

By chat they assured me that they will fix the error as soon as possible, even if it probably won't be fixed with the latest firmware update yet (new firmware coming soon?). We will see. Hope it will fixed in shortly.

Emmediemme · Jul 6, 2017

Update:

This is their reply:
We'll have this forwarded to our FAE department for the any solution we can try to collate or this could be fixed when new update of firmware that will be rolled out. Apologies about this matter and thank you for the patience.