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.


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

  • \$\begingroup\$ 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. \$\endgroup\$ Commented Nov 18, 2020 at 15:24
  • 1
    \$\begingroup\$ 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 \$\endgroup\$ Commented Nov 18, 2020 at 16:23
  • \$\begingroup\$ 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. \$\endgroup\$ Commented Nov 18, 2020 at 16:50
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    \$\begingroup\$ 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) \$\endgroup\$
    – Peter M
    Commented Nov 18, 2020 at 17:22
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    \$\begingroup\$ @CarolynChierico Would it perhaps be more accurate to say that "No images were intentionally deleted while shooting..." \$\endgroup\$
    – Michael C
    Commented Nov 19, 2020 at 7:48

1 Answer 1


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.


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