Tutorials

Hi Ed,
I am by no means an expert on video formats and compressions but I don't think you can translate the 'photographic settings' to 'video settings'. Video cameras, in general, use codecs that compress image sequences, so in fact when you have let's say a 30fps movie, the camera does not literally store 30 frames at 1920*1080 but determines a number of keyframes and uses interpolation algorithms between those keyframes. I think, but don't quote me on that, that the number of keyframes stored is closer to 4. Since all the calculations are done by the camera's processor, the actual writing speed can be much slower. So yes, 8MB is actually enough. I have a x133 card and haven't experienced any issue so far. The 7D has a buffer indicator that only appears if the camera can't write fast enough to the card. I have only seen that indicator once and at its lowest level and only for a second or two. So a x133 works absolutely fine. I picked x133 because it was slightly more than the double of the recommended 8MB/s because you have to account to different qualities in the cards. In my experience anything better than 20MB/s is more than enough for video and it is much more useful to invest in more capacity rather than speed. I hope that helps :)

Thanks Matthew,
What settings did you use to push the limits? I'd be curious to try them out.
I still haven't experienced any issues with my x133 card and, as a matter of fact, just ordered a second one.
Also, quality among manufacturers, not to mention fake cards (rated higher than their capabilities) also come into play. What brand have you been using and did you purchase it from a trustworthy source?

Slower cards will limit the length of each video clip you can product. The camera shoots directly into its internal buffer and from there the data is moved to the card. When the buffer is full, the video stops. Therefore, the faster the buffer is empties, the longer clip you can shoot. The real question is how fast does a card need to be to allow you to fill it up with a single video clip. I don't know the answer, but clearly it is dependent upon how large the card is.

I've got an extreme III now and it works great. I've never hit the buffer. I'd go with that for video.

Peter, 30MB/sec is plenty enough… Canon recommends 8MB/sec, so you should double that just to be fine (16MB/sec). And you have 30MB/sec which is almost the double again… You shouldn't have any problem here

I have the 7D and have been using a 8GB SanDisk Ultra 30MB/s without any problems. I shot basketball indoors for up to about 4 minutes at a time without any problems [stop shoot during dead ball timeouts]….except I filled the card up before the game was over. I agree with Jan…get more capacity…16MB or 32MB card for sure.

From the descriptions I can gather relative to this card it is rated for 30MB/sec (200x). So yes that will do it just fine. One thing I would double-check though is that on all product pictures I saw the rating has a little asterisk next to it (like this 30MB/s 200X*) meaning there must be some fine print. Just make sure the card can properly sustain its advertised speed.

My Canon 7D has problems with 133x card when there is a lot of motion (like a street traffic). I recommend getting at least x200 card.

I have had a 7D for a year and have also had problems with buffering on slower cards. I eventually bought a 8gb Duracell UDMA card for £19.99 from 7dayshop.com, and since then no problems at all.

I bought a 32 gb 133x kingston elite pro (yeah right). Anyone want it? so slow it cannot even take pictures. cannot shoot video.

there is a reason why the faster ones cost so much. Run from this Compact flash!