Understanding CF cards for HD video?
 

For stills I've always had a couple of SanDisk Extreme III 4GB disks. I've never had issues with the cards. Is there anything in particular to look for when dealing with HD in the 7D (Or that people have noticed in their 5Dii)

This page may be of interest:
Levi Buzolic CompactFlash for Canon 5D Mark II Video

The transfer rate of the 7D is probably very similar to the 5D Mark II

Jason,

I've always used the Extreme III in the 5d2 (video) with no problems. I wouldn't go any slower than that, but I don't think you need to go faster either (unless you have extra cash). Bear in mind that 4gb is only 12 minutes recording time in HD (assuming 7d will be same as 5d), so you'll need a few cards. Currently I use 2x 8gb and 1x 4gb, but will be picking up another 16gb Extreme III, as I'm using the 5d more and more and shooting HDV less. It's a beautiful thing that the media is reusable, but scary in that with HDV tape (even the best ones) are relatively cheap and you can save your master tapes in case of disaster. It's troubling sometimes to re-format CF cards when you've got important footage on there (back-ups to multiple hard drives now).

I and several others on here use Kingston Elite Pro 32 GB 133x CompactFlash Memory Card for video on the 5dmkii. They are cheap and have been very reliable to date. The only negative I haven't been able to quickly take a still pic while video recording.

Does anyone prefer the Extreme IV cards. Do they make a difference?

Peter

UDMA for stills during video?
 

I forget where I read it, I think in a CF Card review on B&H, but someone was saying that his Extreme III or equivalent was great except for when taking a still during HD video recording -- that it would cause a bit more of a delay and a few occasional lost frames compared to doing the same with a UDMA-enabled CF card like the Extreme IV, Hoodman Raw, Ridata 32 GB UDMA, etc.

I think I'll have a 16GB super-fast UDMA card or two for my main photo/video cards, and then multiple more affordable 32GB fast cards for extra video shooting in the field, and a UDMA-enabled CF card reader for my MacBook Pro Express Card slot, if there is such a thing, or at least a Firewire UDMA CF card reader (faster real speed than USB 2).

New SanDisk Extreme Pro. Up to 90 MB/s
 

There are now newer and faster cards than the IV

SanDisk | Products | DSLR | SanDisk® Extreme® Pro? CompactFlash® Card

Peter

Older UDMA card cost cuts, or just bigger rebates?
 

Yes :) ... Just saw the Extreme Pro news on robgalbraith.com -- an excellent pro digiSLR site that also tests CF cards, a MacBook Pro monitors for color accuracy, etc.

Hopefully the not-as-new Extreme IVs and other UDMA cards will drop in price substantially before my mid-October trip to Thailand with my 7D that is on order :)

OK - I need it explained to me like a 4th grader.

As far as we know, will the Extreme III be perfectly fine on the 7D? Is there absolutely any reason to go faster? For example, which of the below would be better:

SanDisk 32 GB Extreme III Compact Flash Memory Card - Pack of 3 for $519.95

or

SanDisk 8 GB Extreme IV Compact Flash Memory Card - Pack of 3 for $299.95

Keeping in mind that switching cards (the time it takes) is not an issue.

For _video_, even the Extreme III's 30MB/s is way more than enough. The 7D is only 40Mb/s (note the lower case b, Megabits vs MegaBytes), which is only 5MB/s.

The main reason for faster CF's is not video, but when you're shooting 8fps of 17mp RAW files. That's 22megs per file, 8 per second or 88megaBytes per second. Now you see why Sandisk came up with the 90MB/s Extreme Pro series.

Bought a pack of 3 SanDisk Extreme III 30MB/s Edition 16GB for 250USD plus 90USD rebate.

With the right card reader extreme IV will copy to the computer faster. On camera a fast card matter to some still photographers. But not for video, as emptying the buffer is not an issue.

Extreme III is a good conservative choice. But only buy cards that say "30mbs" on the front. These are UDMA. There are older extreme III that are not UDMA.

Tim Smith of Canon specifically recommends using UDMA cards. He said that people have reported glitching or banding when using non-UDMA cards, and that those things just don't happen when using UDMA. He said their speculation is that the codec may be dumbing down the bitrate to accomodate the slower cards, and that when using a UDMA card, such "dumbing down" never needs to happen.

I saw the video in which he made that statement. He seems like a very smart man, but how does he as a representative of the company speculate on what "might" be happening. It seems to me a more definite statement is needed-- not the "codec may be dumbing down" . He also made statements about mods to frame rate for the 5D on the chip and other sought after revisions not being possible or feasible. On the other hand, he freely admitted he never thought Canon would even make a change to let the camera go to a manual mode. He seemed to have a lot of experience with the camera-- espeically in the early days before the new firmware, but I am not so sure we can trust his technical pronouncements.

YIKES! ... Was this only with the 7D?
And have any 5DmkII owners experienced anything similar, with the somewhat lower bitrate?

Not that glitches/banding are ever OK in serious usage, but did Smith say how often these things were present and how readily visible they are?

WHY would this happen, when the codec is about 48mBITSsec/6mBYTESsec and Extreme IIIs are 30mBYTESsec and thus should have PLENTY of speed for the 7D's video?!?

Megabits to Megabytes Conversion Calculator