Why does my 5D Mark III suddenly stop shooting pictures?

[tdehan]

Every so often when I am shooting a lot of pictures with my 5D Mark III, once I release the shutter button I am unable to focus or take more pictures for a few seconds.  I thought at first this was because it was writing information to the memory card but that does not appear to be the issue.  The screen also does not indicate that it is busy or writing informatoin to the card.  This issue does not happen on my 7D or 50D.

[TCampbell]

Is the red LED lamp on when this happens?  That would indicate the camera is trying to use the SD card.

Also, I'm wonder if this would happen if you swapped to use a different card.

I would have initially suspect that you've filled the internal memory buffer and it needs time to finish writing out the images in buffer to clear space for more shots ... but it will normally allow you to take another shot as soon as there is enough space in the internal buffer for just one shot (the camera doesn't need to write out everything in the buffer before it's willing to shoot again.)

[tdehan]

If you are referring to the red lamp on the back of the camera, no.  The card I am using in the 5D Mark III is the same one I am using in my 7D, a SanDisk Extreme 32GB Compact Flash

[tdehan]

So, I need to make a correction on the Compact Flash Card.  The card I am using is a SanDisk Extreme PRO 32GB Compact Flash.

I am wondering...I was shooting a wedding this past weekend when this was happening.  The card is rated at 32GB however, the formatted space shows approx 29GB.  The total space used for pictures was just over 27GB.  Wonder if it was stopping because the card was getting low on space?

[RobertTheFat]

tdehan wrote:

So, I need to make a correction on the Compact Flash Card.  The card I am using is a SanDisk Extreme PRO 32GB Compact Flash.

I am wondering...I was shooting a wedding this past weekend when this was happening.  The card is rated at 32GB however, the formatted space shows approx 29GB.  The total space used for pictures was just over 27GB.  Wonder if it was stopping because the card was getting low on space?

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What lens were you using? My 70-200 f/2.8 has two modes. In one of them it focusses faster, but doesn't let you get as close to the subject as in the other mode. If you're in that first mode and you get too close to the subject, the resulting behavior is as you describe. I doubt that that's your problem, but thought it was at least worth mentioning.

If the card were out of space, it would tell you. You wouldn't have to guess.

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[tdehan]

The lens I was using was the Canon EF 16-35mm f/2.8L II USM.  And the card was not out of space... just getting close

[JonKline]

It definitely sounds like a full buffer.  The 5D mark III uses a different memory controller than the 7D, so they interact with the card differently.  Plus, I'm pretty sure the raw files from the 5D3 are bigger.  You might have better results with a different CF card, especially one rated 1066x.  

[tdehan]

I upgraded my memory card to a Lexar Professional 1066x 64GB CompactFlash card thinking it might solve this problem.  However, when shooting an event this past weekend, my 5D Mark iii started doing the same thing again.  Once the card was about 75% full, the camera would stop focusing and or shooting unless I shut it off and then on or changed settings.  This is really odd.  As mentioned, neither my 7D or 50D do this.  I am shooting in RAW and yes he files are large but I can't figure out why this is happening.  It has caused me to miss a number of shots.  Any other ideas or suggestions would be appreciated.

[cale_kat]

It is possible that the camera sensor "heated up" and the 75% usage is as much a guage of time used as "capacity" used.

If you fill a 32gb card to 3/4 full in a relatively (don't ask me what this means) short time, it's possible you're just shooting fast enough to cause the sensor to get hot and need to cool.

[tdehan]

That certainly makes sense.  However, in this case the card is not getting filled up in a short amount of time.