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Context & Problem

Shooting with a Nikon D810 with two cards:

  • 64GB compact flash (Sandisk Extreme)
  • 32GB SD card (Sandisk Extreme Pro)

The camera is set set to write to both in Backup mode. I photograph criminal scenes and it's crucial these are captured securely and in sequence.

After photographing a scene, and in review of the cards I found two issues:

  • The first two images were on the compact flash card but missing from the SD card.
  • A random image in the sequence (image number 34 in a sequence of 60 images) was missing from the compact flash card but on the SD card.

No errors appeared at the time of shooting and cards were formatted in camera prior to shooting.

Question

What can cause this to happen? And how do I assure this doesn't happen again in the future?

Saaru Lindestøkke
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Carolyn Chierico
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  • Hi and welcome to Photo.SE! Interesting question, I've never used dual card cameras so I can't answer. However, did you check the web if other people have reported the same issue? It's very much appreciated when question askers show their research so far, so answerers can suggest new things which have not been looked into yet. – Saaru Lindestøkke Nov 18 '20 at 15:24
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    yes I have looked extensively online but haven't seen anything referring to this issue.or I am not searching correctly (hence I'm asking specifically) thx – Carolyn Chierico Nov 18 '20 at 16:23
  • Good to hear you've looked online already. I've also had a brief read and found there are multiple ways of formatting the cards in camera (through a menu and using two buttons). Could you edit your question to include how you formatted the cards? Perhaps that's useful information for answerers. – Saaru Lindestøkke Nov 18 '20 at 16:50
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    An obvious question. Did anyone attempt to delete these images from the camera? This question suggests that with Nikon D750 you have to explicitly delete an image from both cards in order to completely delete it. IE do two separate deletes - one for each card. Thus human error could explain image appearing on one card and not the other. (Some of the comments suggest that Nikon's reasoning for this behavior is to protect against human stupidity) – Peter M Nov 18 '20 at 17:22
  • No images were deleted while shooting (no images can be deleted during a scene shot as per procedure) – Carolyn Chierico Nov 18 '20 at 17:34
  • the cards were formatted using the two button method. – Carolyn Chierico Nov 18 '20 at 17:51
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    @CarolynChierico Would it perhaps be more accurate to say that "No images were intentionally deleted while shooting..." – Michael C Nov 19 '20 at 07:48
  • If the card has not been reused since the shoot, the deleted image is probably still stored in a memory location on the card, it's just not showing in the file partition table. I'm sure your department has folks who are experts at recovering "deleted" files from memory cards and hard drives. One of those tools specifically geared for image recovery (SanDisk Rescue Pro, Lexar Recovery Tool, Piriform Recuva, etc.) should be able to find and recover it. – Michael C Nov 19 '20 at 10:01
  • @MichaelC The image still being on the card is predicated on the assumption that it was deleted (intentionally or not). Without a full analysis there is still always the possibility that a glitch of some sort precluded the image from being written in the first place (as cameras do destroy cards on occaision). However a full forensic file analysis of both cards would provide some interesting data points. – Peter M Nov 19 '20 at 14:48
  • I'd say the likelihood of an unintentional sequence of button presses (perhaps while holding the camera and doing something else, such as filling out a form), is far greater than an internal camera glitch that wrote an image to one card but not the other. It's also possible the camera did write the image, but to a bad sector on the card. Both the first and third possibilities could be revealed through a full forensic file analysis of the card. – Michael C Nov 20 '20 at 00:40
  • A deleted image may not be recoverable if it was overwritten by subsequent shots, which is likely, if the deletion happened before the full sequence of shots was completed. By the way, it seems to me this is a question best put directly to Nikon. – Victor Engel Jun 26 '21 at 01:24

1 Answers1

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I have a D810 and have experienced this problem early in it's ownership. Likely it is due to one of the cards having a speed rating that is too slow to obtain the desired performance.

Upgrade the slower of the two to something better and that will probably fix your issue.

jones0610
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