CMOS Sensor Overheating

M

MarcoPolo

Active member
I have read that the 5D sensor overheats in about 14 minutes, but how long does it usually take to cool off before you can switch out the SD card and resume shooting?
 
I've shot 3 hour classes recording back to back with three cameras. No overheating or cooling down.

You mention SD card, are you sure you mean the 5D?
 
I've seen it mentioned in several online articles concerning DSLR work flow. Perhaps I confused the length of recording time available on a memory card with the overheating of the sensor. The memory card has nothing to do with the overheating as far as I have read, but if it was overheating that often, it would make sense to use that downtime to reload.

To rephrase, how much shooting time is available on a 5D until the sensor requires downtime to cool off?
 
MarcoPolo said:
I've seen it mentioned in several online articles concerning DSLR work flow. Perhaps I confused the length of recording time available on a memory card with the overheating of the sensor.
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You seem to be confused on multiple points. For one thing, there is no limit to "length of recording time available on a memory card," per se. You can record up to the capacity of the card, and in the case of 32GB cards, that's over 90 minutes. However, each clip can only be a maximum of 4GB in size. The camera uses a somewhat variable bit rate encoding scheme, and at average bit rate, 4GB is about 12 minutes. But if you shoot a clip with very little change in imagery, you can get up to 14 minutes. That's what people have found.

Once a clip has reached 4GB, the camera stops recording. You may restart recording immediately. I'm not sure where you got the idea that you can only record 14 minutes on a memory card. Users would be making a much bigger deal out of it if it were true.

The memory card has nothing to do with the overheating as far as I have read, but if it was overheating that often, it would make sense to use that downtime to reload.
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Since you were confused on multiple points, this is irrelevant. The overheating issue has been overstated, and most users have found that the camera rarely overheats, or does so once every few hours, if conditions are right. I can't imagine how you got confused like that. There's barely any logical connection between overheating and recording times, per se; at least there's nothing that would suggest that overheating would be so frequent.

To rephrase, how much shooting time is available on a 5D until the sensor requires downtime to cool off?
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It's unpredictable. But if you shoot in a cool environment, and deactivate live view in between takes for a minute or two, then the camera will almost never overheat in the middle of a take.

By the way, the 5D uses Compact Flash cards, not SD. I'm not sure where you got that information either.
 
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ydgmdlu said:
There's barely any logical connection between overheating and recording times, per se; at least there's nothing that would suggest that overheating would be so frequent.
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I've found it's not frequent at all, but having the sensor *active* is a pre-cursor to overheating...so long or continuous recording would be a contributing factor I would have thought....

jb
 
i have had the 5D on for hours on end... all that happens is as the CMOS heats up, the apparent sensitivity decreases slightly (1/4 stop), and the image gets a bit grainier. (slightly)
 
TimurCivan said:
i have had the 5D on for hours on end... all that happens is as the CMOS heats up, the apparent sensitivity decreases slightly (1/4 stop), and the image gets a bit grainier. (slightly)
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Well not just that actually. You may also get a kind of jerkiness in the video, where it is suddenly dropping frames all over the places. This is especially true if you are doing a lot of panning. In this case I just turn the camera off for a couple of minutes and it's usually fine afterwards.
 
Stop thinking about it and do some tests there are too many rumours on here if you took notice of most you would leave your camera in its box and sit in a windowless room crying.
 
TimurCivan said:
i have had the 5D on for hours on end... all that happens is as the CMOS heats up, the apparent sensitivity decreases slightly (1/4 stop), and the image gets a bit grainier. (slightly)
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I guess this is one of the things that still makes having the 5D Mark II for video a good thing.
 
Thanks for the info, it cleared up some of the confusing information I ran across. The 4GB file limit seems to have been the main issue I was reading about. It's very impressive that you can load 90 minutes of such nice footage onto a 32GB card.
 
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