Canon 5d Mark Ii Memory Card Slot

Two card trick

Back in 2004 when the first EOS camera with dual card slots – the professional EOS-1D Mark II – was launched, media cards had a much smaller capacity than nowadays, so having the extra memory accessible without changing cards was important. But there are other benefits to having two card slots in your EOS camera than simply doubling your shooting capacity.

Nowadays, having two card slots in your camera is not so much about the capacity. After all, with cards readily available (and fairly affordable too) offering 128GB, and the current maximum standing at a huge 512GB (as at February 2019), running out of space mid-shoot is the least of our worries.

Instead, having access to two cards gives other options, such as in-camera back-up, the ability to record different file types to each card, and more.

So, how do you access these features?

Which cameras feature two media card slots?

DSLR: EOS-1D Mark II, 1D Mark II N, 1D Mark III, 1D Mark IV, 1Ds Mark II, 1Ds Mark III, 1D X, 1D X Mark II, 1D X Mark III 5D Mark III, 5D Mark IV, 5DS, 5DS R, 7D Mark II

MIRRORLESS: EOS R5, R6

Record func+card/folder sel.

On models such as the EOS-1D X, 1D X Mark II, 5D Mark III, 5DS, 5DS R, 5D Mark IV and 7D Mark II the options to record to the two different card slots has become a complex menu as there are different ways you can set up your camera to use them.

item3 When you enter the SETUP menu – indicated by a wrench or spanner icon – and select Record func+card/folder sel. there are three options: Record func., Record/play and Select folder.

Here's what each option does.

1) Record func.

This function allows you to choose how the images are recorded onto the two cards. The default is standard. There are also options to switch cards, record to both cards or record different formats to each.

Where only one card is fitted in the camera, these settings are overridden.

QScreenEOScamera Drivemodeselectionscreen

Standard
This will record to and play back from the card that is set in the record/play menu setting (see 2 below). If there is only one card fitted it is that card; if two are fitted it can default to the first one inserted when the cards are put in if the camera is left on or one card has been removed.

It doesn't matter whether the camera is set to record RAW, JPEG or both – whatever file format the camera is set to record will be to that nominated card.

Auto switch card
(Not available on EOS-1D Mark II/N or 1Ds Mark II).
When this setting is active the camera will record and play back to the nominated card, so long as there is space on the card. If that card becomes full it will seamlessly switch to using the other card. In the days when the cards were a lot smaller this was useful; today with 64GB and 128GB cards available it is rare to fill the main card up.

Rec. Separately
(Not available on EOS-1D Mark II/N or 1Ds Mark II)
This option is only relevant if you shoot more than one file format, i.e. if you are shooting both RAW and JPEG and have two cards fitted. This allows you to record the RAW files on one card and the JPEG files on the other.

To set which format records to each card, go to the Q screen, then select each card in turn, choosing the preferred file format. This is useful if, for example, you normally shoot JPEG, but like to have a RAW file just in case. One downside with this is that you have two cards to download if you intend to keep everything you shoot.

Rec. to multiple
This is the belt-and-braces approach. This option records whatever file formats you've selected to both cards, giving you two identical copies of each file, if you then download both cards. On the plus side, it gives reassurance if you're concerned that a card might fail. However, you need a good stock of media cards and time on your hands to manage the file duplication successfully.

2) Record/play

Selecting this menu item allows you to specify which is the main card where two cards are fitted. Exactly what options appear will depend what the first menu item – Record func. – (1 above) is set to.

If Record func. is set to Standard or Auto switch card, then you'll just have the option of the two cards. If set to Rec.separately or Rec. to multiple, then it gives the options of which card you want to play back from.

3) Select Folder

Here you can create your own folders in which to store your images on the media card, rather than allowing the camera to do this automatically. When you enter this menu item you will see a list of folders currently on the card. The active folder is highlighted and the camera will allocate the next folder in sequence. To select the folder you want to record to, highlight the folder and press set.

This makes sense if you download your images manually (e.g. with a card reader, by dragging them from the card to where you want them on the computer). If you let one of your programs download automatically this information often becomes hidden or lost altogether as most programs utilise date information for filing.

Shots remaining count

When Rec. separately or Rec. to multiple is set, the number of possible shots available will be from the card with the lower capacity. When either of the cards becomes full, 'Card full' wil be displayed and no further shooting is possible.

To use up the capacity on the card which is not yet full, switch the recording method to Standard, select the relevant card and continue shooting.

Which camera accepts which card types?

Camera model	Slot 1	Slot 2
EOS-1D Mark II	CF	SD
EOS-1D Mark II N	CF	SD
EOS-1D Mark III	CF	SD
EOS-1D Mark IV	CF	SD
EOS-1D X	CF	CF
EOS-1D X Mark II	CF	CFast
EOS-1Ds Mark II	CF	SD
EOS-1Ds Mark III	CF	SD
EOS 5D Mark III	CF	SD
EOS 5D Mark IV	CF	SD
EOS 5DS	CF	SD
EOS 5DS R	CF	SD
EOS 7D Mark II	CF	SD