Memory Cards for Canon 5D mk3


Sep 17, 2013
Hi everyone,

I own a Canon 5Dmk3 and a Canon 7Dmk2. I have 2 Sandisk Extreme 60mbs 32gb CF and 1 Sandisk Extreme 60mbs 16gb CF. I also have 2 Sandisk Extreme 30mbs 8gb SDHC.

I want to replace my 16gb CF by a 32gb CF and I want to buy 3 new SD cards of 32gb.

What kind of cards do you recommend? What speed? Quality? Knowking that I might buy a 1dx or the future 5Dmk4. I dont want to use the CF and SD in parallel but I intend to use the SD cards as backup when I travel. I have never done it with my cameras but If I am not mistaken, on the 5Dmk3 it is possible to transfer all the photos from a CF to a SD.

All comments and advices are appreciated. Sorry if I made any mistake, english is not my mother tongue.



Mt Spokane Photography

I post too Much on Here!!
Mar 25, 2011
I'd go for larger cards, at least 64GB. I also would not buy a whole bunch of them, since technology is changing and any new models like the 5D MK IV might use a more advanced card.


Canon 1Dx
Oct 25, 2012
Is there anything wrong with the cards that you have now? Are they limiting you in any way?
Fast cards are great but they are expensive and there is a limit to what speed cards your cameras can take advantage of.
If you do get a 1DX then I can heartily recommend the Lexar 1000x or 1066x cards as they significantly increase the numbet of frames in a burst and the buffer clears very quickly. However I would only look at these if/when you get a 1DX as they will be cheaper then.

There are some tests that may help here:


May 4, 2011
I swear by the Sandisk Extreme Pro CF/SD cards (I use 64GB cards in the 5D3 and 128GB cards in the 7D2). Pricier, yes, but the speed is worth it to me.

If you're not doing action/sport/burst shooting, though, probably doesn't matter as much what card you use.


Sep 15, 2012
Good answers above. It's futile (and expensive) to try to future-proof card purchases. Just ride the technology wave of the higher-but-not-top end. Don't pay premiums for the very latest. Excepting currency/economy fluctuations, cards tend to be cheaper when you come to upgrade anyway.

The 5D3 is old now and its card interfaces are a mixed bag (notorious pre-UHS-I SD). If you buy to get the higher-end for the 7D2, that will be a good rule of thumb:

For historical purposes, a nice short summary for the 5D3, fairly up to date (2014), including the issue of not using CF and SD simultaneously for better performance:

BTW, something people tend to overly focus on is the WRITE speed of the card during shooting. That is also complicated by the buffer internal to the camera which is actually what is filled first (during a burst of stills).

That importance varies depending on what you are trying to do, but another benefit of faster cards is the convenience of fast READ when it comes to downloading the results onto your computer. Some people don't care about that phase but for others that can be just as important. Only you can decide, for your use case.

FWIW, I use ~1000x 32GB Lexar cards on 5D3. I'm moving to 64GB ones now I also have the 7D2 (refurbished bargain, yay!) for action. Looking for good deals during imminent holiday season in the US.

BTW, I stopped using the SD cards on the side in the 5D3 because of crappy performance, even though I appreciated the back-up safety for a time (I lost a nearly-unique CF-only shoot completely because I originally used no SD backup). Now I have the 7D2, I may go back to doing that on both as I don't need the fastest speed on the 5D3 so much now and I haven't heard the 7D2 had the same 2-card slow-down issue as the 5D3 did.


Oct 23, 2012
The SD slot in the 5D3 can only be used for smaller JPG files for transmitting through a WiFi card to an external device. Canon hooked it up yo an internal USB in the camera and that USB is slowing down the rest of the camera so I don't advise to use it else than for backup or/also transmission.


Sep 17, 2013

Thanks everyone for your replies.
I don't intend to use the SD card in parallel with the CF card. But it is a cheap way to have a copy of all my images when I am on safari. Logistic can be a nightmare. Weight limit of hand luggage, lack of charging facilities...
My present cards have nothing wrong. But I think that having 3CF of 32gb and 3 SD of 32gb makes more sense.
I need fast cards. As you mentioned, I will take the right card fro the 7Dmk2 which should be fine for the 5Dmk3 too.

Thansk again.