The Nikon D800 / D800E have dual card slots; one Compact Flash slot and one SDXC slot. Ditto for the Canon 5D Mark III.
Nikon D800 / D800E
The manner in which the dual slots are to be utilized in the D800 is configured via:
- RAW Primary; JPEG Secondary.
For example, one could use these two cards in a D800 / D800E. I set the CF card to the primary, because it is the fastest card.
The Nikon “Overflow” option
For my purposes, this is the only useful option and has been of value in the field.
For example, three miles down a canyon in Yosemite, I realized that the CF card in my D800E had filled to capacity, and the D800E was now using the SDXC card.
The overflow option to the SDXC card saved me a strenuous return hike to get another card (I screwed up by not checking in advance and by not taking more cards, but mistakes can be made!).
The Nikon “Backup” option
Nikon’s “Backup” option is an effectively useless feature for my needs because deleting an image leaves its counterpart on the other card. With some images doubled-up and some single, reviewing images is thus hopelessly confusing, with desired images intermixed with unwanted ones.
The Backup option requires twice the effort to delete an unwanted image. Since I often shoot a frame to check the histogram and/or need to delete a sequence of 6-8 images, this becomes an untenable amount of chimping (6-8 images becomes 12-16 images to delete using the mirror option).
If the same file is written to both cards, deleting it ought to delete it from both cards, not leave a confusing mix of files.
The Nikon “RAW Primary; JPEG Secondary” option
I never shoot JPEG so this option does not concern me, but I presume it works the same way as the Backup option (confusing).
Bernard L writes:
You seem to see little value in the back up function of the D800 (storage to both CF and SD cards simultaneously).
I personally find this to be one of the most important capabilities of the camera and I have been feeling this way since the D3, more than 5 years ago. I have had at least 2 occurrences of CF cards go bad on me, both times during once in a life time trips, and this capability just saved my day and enabled me to preserve some very important images.
The fact that it is a real back up and not just a raid approach with images being deleted on both cards is also a feature since I did delete by mistake images from the CF more than once. Knowing that the file was still there on the SD was critical also.
DIGLLOYD: For the way I shoot, the display bug (deleted images being shown) is irreconcilable with working efficiently. This is not to say the feature might not appeal to others. This issue could be reasily resolved with a custom setting, should Nikon choose to do so.
Opinions from readers range from effusively enthusiastic to ones like this from Christian S:
This “feature” is mindnumbingly stupid. One could even consider it broken in a way that renders the whole backup function useless.
I made it part of my workflow on shootings to delete subpar images during downtimes since it speeds up the importing & picking process by a fair amount. During a long session I may delete a lot of images. This means that eventually the backup card runs full without me noticing anything about it.
This is kind of hard to describe, but note that if you only navigate in between the shots you have taken (resp. you’re at the last shot and go back from there without surpassing the first shot) without “spilling over” you’ll never even see the backup shots, so you cannot simply delete them by double-tapping delete. It’s pretty bad.
I wonder if you came up with any workaround for the problem. I’m considering of going back to filling several small cards instead of using the backup function.
DIGLLOYD: I no of no workaround, and I lean towards the “mind-numbingly stupid” opinion of the implementation. And why isn’t there a “clone card A to card B” feature built-in, so that a backup can be made at will? Including a smart update that copies only newly added files (or everything if need be). It’s just software.
But since it took Nikon 5 years to fix a brain-dead Live View implementation (mirror slap for blurred images, still not fixed for self timer though mirror delay helps) and replace it with a mangled Live View mode in the D800, I no longer expect much more than mind-numbingly stupid design from Nikon (and that’s not hyperbole) when it comes to anything but core camera features.
Canon’s “Rec. to Multiple” implementation
I have not investigated all the Canon permutations—
Canon’soption in the EOS 5D Mark III does it better displays only the primary card contents so the confusion issue noted above is avoided (but becomes confusing if one chooses to view the alternate card). The display-primary-card approach avoids the confusion, but the image which is deleted from the primary card still remains on the 2nd card; it is not deleted.
If one acceptsas meaning “Backup”, then this makes some dubious sense, though it’s not what I would prefer: I want both copies deleted; backup is for (a) card failure or (b) “FedEx one card home”. I don’t want the secondary card filled with images that I had already chosen to delete.