I am looking to get a second SD card to fill both slots in my d7000. The card I have now is a remnant from my canon point and shoot that I am using in my d7000 now.

I have yet to try movie mode. And I have not yet tried to shoot raw images.

The card I have now is a 32 gig class 10 Transcend that has worked well so far. Also, I know some of you have mentioned to avoid them but for the price this seemed like a great value and has worked flawlessly for me for about a year now. And, i would wager not all class 10 cards are created equal. My feeling is some are faster than others even though they carry the same class rating.

I have read many reviews on Amazon of various cards and find the sporadic user who sees HD video pause while recording.

since I will eventually be using HD video recording and plan to try shooting in RAW this weekend at a wedding (not as a hired pro but just as a guest) I wanted to make sure if my current card is not fast enough that I get one that is in time for using it and not having problems when they can hurt me most.

What of the two actions is more taxing on the camera system HD video or RAW in burst mode?

And will my card be able to handle both?


4 Answers 4


HD video will be far more taxing than shooting RAW in burst mode. The reason is that the camera has to compress video constantly and write to the card nonstop for the entire time that you are recording video. If it gets behind, there's no break in the action for it to catch up. When you're using burst mode, eventually the camera will ratchet back your fps in order to attempt to catch up.

My question for you is why aren't you testing yourself whether your card is able to handle both? Inside of 10 minutes you should be able to shoot a lengthy HD video clip and several RAW bursts in order to be able to get an idea of what your card is capable of handling reliably.

  • 1
    Recording video is certainly more intensive on the image processor but I'm not sure the camera has to write the data back to the card constantly, given it has a buffer large enough for about 10 RAW files (~200MB) it seems reasonable that there is some sort of buffer for video. When the Raw buffer runs out you usually only get a shot every couple of seconds so I don't think this behaviour still counts as "burst mode". Video recordings can last for 20 minutes, so I'd say this is less intensive for the card.
    – Matt Grum
    Jan 5, 2011 at 21:42
  • 1
    Fair enough. I think the 'Go test it you lazy bum... Don't con other people into doing your homework for you!' (all intended in good fun, of course...) part of my answer was the real point I wanted to make. ;-) Jan 5, 2011 at 23:08
  • Providing the questioner him or herself with an answer is only part of the reason for posting on stack exchange, the answer also stands for anyone else who stumbles across it. The question of which is most demanding of the flash card is a legitimate one for someone unfamiliar with video bitrates, and they might not own a video capable DSLR to do their own tests.
    – Matt Grum
    Jan 6, 2011 at 23:34

Your camera's user manual recommends at least class 6 SD cards. (It also lists "approved" memory cards.) You have a class 10, which is faster. So why not just shoot a few minutes of a movie right now and verify that it works fine?

  • software products (like windows) also recommend minimum specs, but as we all know they are not nearly enough for things to run smoothly.
    – kacalapy
    Jan 5, 2011 at 19:48
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    Right: that's why it's a good idea to try it out. But you now know your card nominally exceeds minimum specs, so there doesn't seem to be any reason not to take the next step. If you're looking for details of people's experiences with SD cards, that's already available: look at photo.stackexchange.com/q/4902/1356 .
    – whuber
    Jan 5, 2011 at 19:50

Recording HD video is more taxing on the cameras image processor, whereas shooting Raw in burst mode is far more taxing on the file system / SDHC card.

It's easy to see why this is the case, the camera does very little work to encode the Raw data as no (or next to no) processing of the image information is performed.

On the other side of the coin, your camera probably records HD video at about 5MB/s (ballpark figure based on my cam) whereas each Raw file will be around 20MB, so you only need to shoot one Raw every four seconds to match the rate at which data is written to the card.


The anecdotal evidence I hear on motion-shooting forums is that the Transcend Class-10s are good.

And yes, motion shooting is definitely more demanding on the card. Burst mode simply stores the images in the camera's RAM and then when you're done writes them out to the card at the usual single-shot speed. Problems with motion shooting do not mean you'll have problems with burst mode.

My biggest advice from years of event shooting is to get more cards. They do fail. You will lose pictures at some point in your career. I always made the habit of switching cards periodically during events so that if one did fail or get lost or damaged I wouldn't lose the whole event.

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