Anyone have this happen and know the cause?

What were the circumstances? Camera type, etc...

First thing I'd consider is the age of your batteries, if it starts to become more frequent it's generally the batteries failing due to age.

Another cause might be the presence of a strong electro-mechanical field, or possible proximity to a powerful radio transmitter.

Anyone have this happen and know the cause?

It's a bit of an open question given that we don't know anything about the gear or the situation.....

What were the circumstances? Camera type, etc...

Canon 60D Canon 7D Sandisc and Transcend (both a few months old). Batteries are a year old but the problem doesn't happen that often.

Card dropout? :-)

(Sorry)

Hey Mike..

I used to get a similar message on my 550d's ... Not sure if this is the same problem that your having. Now I do a level format on my cards and I haven't had any problems since. best of luck with it.

Steve

After you've tried Stephen's suggestion, which may be the cause, I'd still think about batteries next, since Lithium Batteries age whether they are used or not, and few manufacturers guarantee them beyond 18 months.

Your year old batteries may have sat on a shelf for six months, if you've never experienced the fault inside the first six months of use but after six months it is starting to occur I'd be thinking about battery life.

What class was the card?

If you are using anything less than Class 10 then your buffer could fill once in a while. Do you ever see the buffer indicator showing?

I have lots of cards from Class 4 to Class 10. The Class 4 actually work most of the time but the record LED is on 90% of the time. Occasionally they stop.

My class 6 cards work 99% of the time (LED is on about 60% of the time) but occasionally the buffer will fill (once ever 200GB or so).

Class 10 cards just seem to work 100%.

I have Class 6 and 10. I do see the buffer warning bar on the side of the viewfinder. It's rare that I get this message but always seems to happen at the worst time of course.

I have Class 6 and 10. I do see the buffer warning bar on the side of the viewfinder. It's rare that I get this message but always seems to happen at the worst time of course.

That would be the cause.

So, does this pause happen with both Class 6 and 10, or can you say for sure it's only happening with the Class 6?

Class 10 is definitely the more reliable for keeping the buffer low.

I see you mentioned the 60D. Part of the issue with buffering is that the 7D has two processors whereas the 60D only has one. This results in less internal heat within the camera but also affects the speed of writing the data at times too.

Same thing has happened several times when shooting with slower cards and the buffer has filled. I've had a buffer warning show on my faster cards a few times, but doesn't stop recording. What's being recorded also plays a part as more information and things going on vs. a static shot with no one moving can make a difference with certain cards.

What specifically were you shooting when this happened and what was the environment? (in particular, what was showing on the screen and where were you shooting at)