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which CF for 7D ?

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jhuynh

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user manual says that write speed is 8 MB/s on the 7D

would cards faster than Sandisk Extreme III be a waste of money ?

does video require very fast cards ?

thx
 
I have both the extreme-3 30 meg/sec and the new extreme 60meg/sec. Its faster to clear the buffer with the 60meg/sec card. I dont think shooting movies makes much differance. I have shot with both cards just fine at 1080 30 fps. I havent yet tried any of my slower cards with movies. So faster cards do transfer faster in the camera.
--
http://www.pbase.com/dc9mm

 
The big viarity of "extremes" is reduced.
Sandisk has intro. a new UDMA 60 mb/sek.
Price is equal to the "old" ordinary Extreme II.

Everything > 15 mb/sek makes no differense in the 7D, but helps download to PC through a card reader (with UDMA support)
--
Canon since 1959 (and a Finepix F10 just in case)
http://www.flickr.com/photos/fujicanon_photo/
 
Erik i dont agree about anything faster than 15 meg a sec makes no differance in 7D. Mine does. My 30 meg a sec extreme doesnt clear the buffer as fast as my 60 meg a sec extreme. I timed them both. In the same amount of time say 30 seconds i can get more raw shots with faster card. I did this a while ago i dont remember what the numbers were but there were more shots with faster card.
Erik Johansen said:
Everything > 15 mb/sek makes no differense in the 7D, but helps download to PC through a card reader (with UDMA support)
--
Canon since 1959 (and a Finepix F10 just in case)
http://www.flickr.com/photos/fujicanon_photo/
Click to expand...
--
http://www.pbase.com/dc9mm

 
A UDMA 30mb/60mb will clear the buffer significantly faster if you're shooting a large burst. For some types of shooting (BIFs for example), it could make a huge difference.

What you said is true for video. Super fast cards offer no real benefit except perhaps in transferring the data off to a computer, and even then, questionable.
Erik Johansen said:
The big viarity of "extremes" is reduced.
Sandisk has intro. a new UDMA 60 mb/sek.
Price is equal to the "old" ordinary Extreme II.

Everything > 15 mb/sek makes no differense in the 7D, but helps download to PC through a card reader (with UDMA support)
--
Canon since 1959 (and a Finepix F10 just in case)
http://www.flickr.com/photos/fujicanon_photo/
Click to expand...
 
OK. Canon claims continuous 126 frames (jpg's) with any UDMA card > = 15 mb/sek.
Canon has no information about higher prosessing speed.
Then, it's probabely the DIGIC itself who are the limit; according to Canon.

I have heard that someone, like you, have measured a differense between writing to 15 or 50 mb cards, actual figures I haven't seen though.
--
Canon since 1959 (and a Finepix F10 just in case)
http://www.flickr.com/photos/fujicanon_photo/
 
I've bought this card yesterday (16Gb) and it is lightning fast, even for multi RAW and video.
Recommended !

 
Hmmm if you would go check you would find that Erik is correct up to the buffer full point. When the buffer is FULL (22 large raw or a zillion jpg's) the faster card will help but ONLY when the buffer is full. Try it, shoot Raw till you get the full buffer slow down then stop for 3-5 sec and try again (before the buffer is empty) the speed is back to 8fps till the buffer fills.

So what this means is as long as the buffer is not full Erik is right but once the buffer is full the higher speed helps a lot.

Dave
 
Video does not require a fast card. I've easily recorded 1080p on a super slow 80x (12MB/s) card. I think your really only need a fast card if you are going to shoot a lot of consecutive bursts of 8 fps still shots. As others have noted above, the buffer will clear much more quickly with a fast card allowing the next burst to be taken sooner.
 
Umm, well, I would have thought that to be sort of obvious, so I failed to mention it. The CF card doesn't really even come into play with respect to speed until you've blown past the buffer. Otherwise, you're simply reading and writing to the buffer directly and the camera is working in parallel with the CF card. Won't affect the rate at all.

My comments were directed towards what happens when you shoot enough consecutive images to fill the buffer. Then, the CF speed makes a big difference. If you're not planning to do that, yes, it probably won't matter all that much.

Jerry
davel33 said:
Hmmm if you would go check you would find that Erik is correct up to the buffer full point. When the buffer is FULL (22 large raw or a zillion jpg's) the faster card will help but ONLY when the buffer is full. Try it, shoot Raw till you get the full buffer slow down then stop for 3-5 sec and try again (before the buffer is empty) the speed is back to 8fps till the buffer fills.

So what this means is as long as the buffer is not full Erik is right but once the buffer is full the higher speed helps a lot.

Dave
Click to expand...
 
I would go for the fastest you can afford. I found that the 60Mb/s UDMA Sandisk work the best, epscially for video, but they are expensive. Also size is important for video and taking RAW. The 16Gbyte works well for me.

IF you can - also get a CF to SD convertor cards and get a few 8Gbyte SD cards which are verry cheap, nice for emergencies but you cant use them for video or large high speed bursts.
 
Erik Johansen said:
Everything > 15 mb/sek makes no differense in the 7D, but helps download to PC through a card reader (with UDMA support)
Click to expand...
That cannot be true. Tests show that the 90MB/sec write speed cards write at about 75MB/second so it can write much faster RAW images.

Andreas
 
Yes, that is true, you need about 10MB/sec for video, don't know exactly, but I used SD cards on the 500D with no problems.

The biggest need for memory cards is for clearing a buffer, which should make a big difference.
Ansible said:
Video does not require a fast card. I've easily recorded 1080p on a super slow 80x (12MB/s) card. I think your really only need a fast card if you are going to shoot a lot of consecutive bursts of 8 fps still shots. As others have noted above, the buffer will clear much more quickly with a fast card allowing the next burst to be taken sooner.
Click to expand...
 
Tonybl said:
I would go for the fastest you can afford. I found that the 60Mb/s UDMA Sandisk work the best, epscially for video, but they are expensive. Also size is important for video and taking RAW. The 16Gbyte works well for me.

IF you can - also get a CF to SD convertor cards and get a few 8Gbyte SD cards which are verry cheap, nice for emergencies but you cant use them for video or large high speed bursts.
Click to expand...
They are super super slow the CF to SD convertors. But yes for emergencies it could be a nice idea.
 
If you have a computer available I would rather have a DVD burner and burn the CF cards to DVD.

I've standardized on 4GB cards, so that works nicely for me.
 
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