I have had my 7D for over 2 weeks and I have a Kingston 266x CF card. I have filled the card 2-3 times and I have never seen the buffer icon...not even for a second. Then, today at lunch I fire up my 7d with my newly mounted Zfinder on the unit....I Only had it on for 3-4 minutes when I saw the buffer icon for the first time ever. It appeared, filled up and stopped my clip almost instantly. It was only 3 seconds long.

I know my card was nearing being full, and I have read that there can be issues when your card is filling up. So, I backed up everything from the card, and deleted in all. I began shooting again, I shot a few 40-50 second clips, then it happened again. I tried to brush it off. 5 minutes later and it happened yet again. It happens almost instantly....the clip never really get's started and it stops in 2-3 seconds.

The only thing that has changed at all is I was using the zfinder for the first time. I am not sure how this could possibly affect the speed of the card, but it's the only thing that has changed in 2 weeks.

Is there anything I can do to test the card? Any utilities to make sure it is not going bad? I have been a bit slow to switch from tape to solid state because of issues like this that arise....and now my paranoia is back in high gear.

Can anyone help out with ideas?

The Z-finder wont affect your card, that's just coincidence. Try formatting the card, some people reckon you should format after each downloading.

I didn't really think the zfinder could have anything to do with it, however some users have reported over heating of the camera more frequently with the zfinder or similar device that covers the LCD. So I thought heat might affect it? Still, the camera was only on for 3-4 minutes when it occurred so heat is not the likely culprit.

Format your card after every use. That will solve your problem. It has nothing to do with the Z-Finder.

I formatted the card and so far so good. The only thing is I occasionally see the buffer icon pop up. It only has one bar and then goes away. In the previous 2 weeks I had never seen this icon at all! Strange indeed.

That's weird. I only use a 133x, and have never seen the buffer icon, either while shooting 1080/30 or 720/60, or a long burst of jpegs. And I run my camera til it overheats most of the time.

...Try formatting the card, some people reckon you should format after each downloading.

Hmmm, very interesting.

FWIW i have a Sandisk Exterme 60MB/s UDMA model# SDCFX-016G

I've recorded about 7 1/2 hours on the card, downloaded numerous times, formatted sometimes, sometimes not... Sometimes i erase bad shots in camera, sometimes i pre-edit shots in camera...

Playing with fire...maybe i should heed the warning!

ive had the same problems with buffer filling up and recording stopping a few times, or seeing the buffer icon for a second with my Kingston Elite Pro 133x 32 GB..

Recently i've formatted and it hasn't happened again.

I'm wondering is it a good idea to format each time? I guess there shouldn't be any negative effects on the card doing this?

One Canon T1i owner had the buffer overrun problem with Kingston cards that seemed to meet specs listed by Canon in the manual. When he contacted Canon about the problem the techs he talked to advised that the Canon T1i could be "brand picky" and suggested he switch to SanDisk Extreme III.

He did and his problem went away.

And I've seen references to the same problem with Kingston media and the D90.

I've got a couple of SanDisk Extreme IV 45Mbps CF cards for the 7D and one 60Mbps card and I have no buffer problem. I know many get along just fine with Kingston, Transcend, and Lexar but I don't care to take those chances.

I have two 8 gig and one 16 gig SanDisk Extreme III cards and one Transcend 16 gig 133x. All have worked flawlessly.

Hi,

well you are not the only one, I have been getting the same problem on my 133x kingston cards. I alway format, so that is not a fix. They worked fine for the first couple of week, and now they will buffer and stop when the detail gets too much to compute. I suspect that this is a result of the cards not being UDMA or fast enough. I guess a card degrades slightly after use.

It was a bit frustrating as I am shooting documentaries for broadcast, and missed some crucial shots as a result.

I have a transcend 300x UDMA card and never had this problem.

I've ordered a couple of the new Sandisk Ultra 60mb UDMA and hope I never get this problem again.

UDMA is all I can say!

well, I'll be the next to add my name to the list! I have four 16GB Kingston 166x cards, and have noticed on quite a few ocassions now that the buffer warning has come up and stopped the recording. There is no real pattern to it either. Today the card was part full (perhaps about 40%) other times it has been a formatted card and only 7-8 minutes on it when it has cut out!

Am quite surprised as so many recommended them, and even saw them on a Philip Bloom vid amongst his CF cards. I've decided to ditch them for any critical work I'm doing, and only use them as a backup of for short cutaway type shots.

Will probably go for 16GB Lexar Prof 300x UDMA card.

Martin:

I'm retired and not in business or anything critical like that.

But there is no way, even in a personal/hobby situation, no way at all that I would even use those cards for "backup" or "cutaways" or in any role. What would you do if while shooting you realized that shot might be a once in a lifetime thing maybe never to be repeated...

...And you got the buffer, it filled up, and the recording shut down.

Lexar? I've had Lexar media just inexplicably go south.

Don't fool around, if you're shooting anything critical, go with SanDisk or Hoodman RAW both with UDMA.

This seems to be a Kingston thing, I have two Kingston cards and get the buffer over run if I don't do a format and try and use partially filled cards. It seems cards around 30 to 40% full start to do this and I also think after normal use of 6 months you start to see this with Kingston.

Seems to me the moral of this story is don't use that brand of card. Most of my Sandisk and Transcend cards are now over a year old and I've never seen the buffer. I format the card after every use--that's how I delete the data after moving it to the hard drives...put it back in the camera and reformat.