Ì already have 2 Kisgton SDHC class 4 cards (32 and 16GB) and I`m going to buy a T2i.
Will them work?
Thanks

They should work, but maybe not continuously. The buffer may fill before it stops recording.
Buy some Class 6 cards.

Manual said class 6 or better.

Class 4 is a bad bet.

The Canon 5D2/7D/550D,T2i all record in the neighborhood of 40 Mbps.
Class 4 corresponds to 32 Mbps - adequate for all the 25 Mbps and less
camcorders out there, but not for this.

Class 4 for video, absolutely not! Speaking from experience. You'll just get frustrated. I even had some issues with class 6 cards. I use class 10 cards and have not had any issues.

Thank you all for the responses.
Anyway, have anyone had positive experiences using a class 4 card with a T2I or 7D?

Dont do it, class 6 should be minimum for video, why even bother thinking about using class4 ???

Because I`ve got two of them.
Thank you

Ron, just sell the cards!! Technology advances and sometimes we have to cut our losses. Even better keep the cards as backup if you take STILLS with the camera. Class 6 16GB are going cheap, $40. Well worth the gain in performance.

JS

I bought a Sandisk Ultra 8gb class 4 card with my 550d, before I read up on the camera, and noticed some dropped frames on test footage. I've exchanged it for a sandisk extreme III 8gb class 10 and have noticed considerable speed improvement.

The manual recommends a minimum of class 6 for video. If you are using your camera for anything critical I'd invest in at least class 6 cards. IMHO.

Drew

Thank you Drew, Colin and John

My next purchase will be a Transcend 16 GB class 6.

Best

Got my T2i last week and shot with a 16gig class 4. Worked fine. However, now that I've heard the naysayers, I'm going to return my other 16 gig card and buy a class 6 for a wedding I'm shooting this weekend. Thanks for the heads up.

I did not notice any dropped frames. And had not buffering issues shooting about 6 to 7 continuous minutes. So, I'm surprised by the words of caution. But I suppose it is best to follow the manual, which I devoured immediately upon getting the camera.

Is it possible that there are drop frames or just buffer full if level 2/4 cards are used?

Both, I'm afraid.

Picked up a couple 16 gig class 6 cards on Amazon. The Transcend ones. But I've just used both the log and transfer plugin and streamclip on about 4 minutes of clips and can't tell any problems from the class 4 cards I've got.

For my documentary work, these cards may present future problems, so I'll move to class 6 next week. I've got to shoot a family wedding next week, so, I'll use the class 6.

Also, I think that streamclip is just as fast as that new Canon Plug-in. This is based on importing two clips. I like that I can bring the clips in at HDV or other codecs using Streamclip. The only options with the Canon plug-in are Pro-Res 422 and HQ or AIC (which is probably what the HDV one is I'm getting with Streamclip).

I've never used Pro Res with my projects because I've been shooting HDV for the last year and a half.

I've been using SanDisk Ultra class 4 cards on T2i and I haven't had any problem so far. I happened to have it so I started using with the new Canon cam not knowing that it is technically below the recommended spec - class 6.

What confuses me is the actual speed of this card. Although it says class 4, it also notes 15MB/s on it and I wonder if it is fast enough for writing video files. For test purpose I just kept it recording as writing this post and it recorded fine until it reached 4GB size limit (13' 41" length) without the buffer gauge popping up.

I still wouldn't recommend buying a class4 card, but I wanted to share my case of successfully using this unusual class 4 card from sandisk on T2i.