I didn't realise the 5D used CF cards
can someone advise if using an SD to CF adaptor works fine for video? I read somewhere that they can be pretty slow

also any particular data rate would be required if I decide to buy CF cards rather than the adaptor?

as always I appreciate your help
Fed

How about this?

Amazon.com: High Speed CF Compact Flash USB Card Reader for use with Digital SLR, DSLR, Digital Cameras!: Electronics

I think Frederico is talking about an SD to CF adapter that goes inside the camera, similar to a micro SD to regular SD adapter, not an SD card reader.

I don't know if adapters slow down read/write speed or not, but I'd much rather just use a fast CF card in my 5D, than an SD card and adapter (if such thing even exists).

Ah, I get it... like the Hoodman SXS adapters for Sony EX 1&3 cameras. My bad.

Never heard of anything like that for the 5D. Sorry.

Yes Julian thanks that's what I meant. Some people are using those but it's definitely better to use CF clearly.

CF cards data speeds (and prices) vary a lot: anyone has found what the minimum data transfer speed the card needs to be be used for the 5D?
Also is there a maximum capacity limit the 5d will handle (I've seen up to 32 GB around)

Thanks

Rapid stills photography drives the performance of the CF cards on the 5dm2 not video. Do some Googling and you'll find some speed comparisons out there (I did this when I had the same question).

I used a 16GB Kingston 133/x and a 16GB Sandisk Ultra 30MBs in my own speed tests. Both are fine for video and perform above Canon's minimum rated speeds classes. The Sandisk Ultra outperformed the Kingston (as it should) in the high speed stills test. There are others that are even faster... for a price.

For me, reliability is a first order criteria. Speed is second order. I would rather have a slower card that's known to be reliable than another that may be faster and unknown or sketchy reliability. YMMV