Compact Flash Or SD Card - Canon 5D mkIII

IanD

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Evening all,

I've tried to search for the answer but cannot see it, so hope you don't mind me asking.

I was looking to find if it was better using a compact flash card OR an SD card with my Canon 5D mkIII.

My style is portrait, landscape and general, although i'm hoping to get into sports a bit more, so would want the right card, to write and not buffer too much.

I have read that the 5 D mkIII isn't the greatest for buffering, so, a couple of questions from my learned friends....

1) If you had to choose ONLY one type of card, based on this camera, would it be a compact flash or SD card?

2) What's the fastest card I should bother getting, as i've read that the 5D mkIII is not the fastest writing, so don't wan't overkill and extra expense (i'm not bothered about the speed of getting the images onto my laptop, just writing to the card whilst photographing)

Many thanks
 
Compact flash

The buffer on the 5D3 is not massive. Faster cards give you a few more frames before slow down occurs.

These are the results I got when I did some testing when I owned a 5D3. They're the average over several tests.

Can only vouch for Sandisk CF cards with these figures.

60MB/S Max RAW 13. Frames before FPS slowed 17. Time to clear buffer to Max RAW of 13 again 5.5 secs.

90MB/S Max RAW 13. Frames before FPS slowed 21. Time to clear buffer to max RAW of 13 again 4.0 secs.

160MB/S Max RAW 13. Frames before FPS slowed 25. Time to clear buffer to max RAW of 13 again 3.25 secs. This is a UDMA 7 card.
 
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sd card because pins go into CF card so more to go wrong
 
CF cards are the faster of the 2.

For general stuff such as portraits, landsacape etc it won't really make a difference. You would only really notice any difference when shooting high speed and taking lots of shots in quick succession, eg sport, BIFs etc.
 
I use cards in both slots. I save RAW to Sandisk Extreme Pro CFs and Sandisk Extreme Pro SDs for JPEG. Two copies of the image with the larger file written to the faster card. For the fastest saves just use CFs.
 
Thanks everyone, for your helpful advice.

I've just ordered a CF and as i've already got a few reasonably fast SD cards, i'll see how they pan out against each other. Sounds like the CF is definitely the way to go for rapid fire
 
Both, because I care about redundancy, never really seen it as a choice, always seen it as something you ought to do.
 
Thanks everyone, for your helpful advice.

I've just ordered a CF and as i've already got a few reasonably fast SD cards, i'll see how they pan out against each other. Sounds like the CF is definitely the way to go for rapid fire
Definitely, the SD card really slows the CF write speed down, assuming you have a fast CF card of course. I backup to SD after shooting CF all day.
Be careful if you open the card door, I think the camera then defaults to SD card write, although it may be if you remove and replace CF card cant remember but always a good idea to check which one it's writing to after opening the door.
Matt
 
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Same as others have said really, When writing to either both cards or just the SD it slows the buffer down a lot, A fast CF card will burst for lot longer than the same speed SD card will in the camera, which is a shame they handicapped the SD slot.
 
Thanks all - expert responses as ever
 
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