Time to be with your loved ones

Time to be with loved ones

by sat

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

Since I shoot a lot of pictures in Live View mode and from time to time I do some short movies, I've developed a paranoid sensation that I'm going to burn the sensor.

I'm aware that live view mode heats up the sensor and constant heat in the sensor could potentially make some hot pixels. I've never saw the heat warning in my T2i, but I'm still concerned.

Should I be worried about sensor heat? How do you prevent it, besides avoiding live view mode?


I'm offering 150 points for the best horror story/advice/tips about sensor heat. Go go go!

share|improve this question
    
Interestingly, this week was the 1st time I saw the heat warning on my 7D. I was setting up my photo setup (a geometric design comprised of multiple items that need to be carefully aligned). The camera was on the tripod and the setting was made using the remote shooting lifeview on the laptop. After about an hour or two, the red mark appeared on my screen. I turned it down and let the camera cool down for a while (it was late night so it was easier..) –  ysap Jun 3 '11 at 16:46
    
One hour? Wow! Did you get any hotpixels? –  Andres Jun 3 '11 at 20:16
    
Honestly, I don't know (did not actually shoot, just used liveview on the monitor with the grid overlay to test configurations and align the stuff). –  ysap Jun 3 '11 at 20:22
add comment

2 Answers

Yes, and no.

  1. Your camera will shut itself down or put itself in a "cool-down" mode in order to save the sensor from overheating. I've had my Canon T1i warn me, and then shut things down in order to cool off.
  2. Could you develop hot pixels? Yes. (I would tend to the idea that any hot pixels are pixels that were prone to going hot anyway, and so you would have seen them sooner or later. For that matter, my T1i has several hot pixels, and hasn't been used as a video camera extensively.)
  3. Hot Pixels are dealt with using several methods:
    • Pixel Remapping (I forget the procedure to do this or if the newer models do it automatically, but the idea is that the camera will remap your hot pixels and essentially ignore the data from them (averaging in the surrounding data). I suspect this may only work in JPG, though, as my RAW files will still have them occasionally. (Canon's RAW processor, though, did seem to take care of them, so it may just be Lr.) I am not sure if Video gets remapped.
    • Dark Frame Subtraction for long exposures (only for stills)
    • Worst case, you should have tools in your post processor that allows for taking care of those hot pixels in post.
  4. Nearly every sensor has them, and if they don't yet, they will. Just a fact of life in the digital world.

Note that all of the above assumes you are running with Canon's standard firmware and not something like Magic Lantern. If you were doing that, then there would be a larger possibility of doing damage to the sensor if it were to permit the camera to stay on beyond the overheating warning threshold. But if you are an normal firmware, I see no reason to worry.

share|improve this answer
    
i read on a blog recently that dead pixels don't get remapped on video (canon 5d mkII, firmware and blogpost from about two years ago). –  JoséNunoFerreira Jun 9 '11 at 16:59
add comment
  1. All sensors get hot pixels, not only in video mode. The RAW processor automatically fixes these.
  2. Overheating your sensor will not lead to permanent damage.
  3. The hotter your sensor becomes, the more noise there will be. This is not a severe problem but still something to be aware of.
  4. There has been a lot of serious work done with 5Ds, 7Ds and the rest. There hasn't been wide reports of problems when shooting - when a sensor overheats, you wait for it to cool down, then continue.
share|improve this answer
    
"The RAW processor automatically fixes these"? Are you sure? Where did you read that? –  Andres Jun 9 '11 at 14:35
    
I have read it in numerous places, also know it from experience. Often you see a dead pixel in the JPEG if the camera didn't fix it, but you don't see it when you open the RAW file. Probably not all RAW processors fix it, but at least Canon's, Nikon's and Adobe's do so. –  Boris Jun 9 '11 at 15:29
    
From my experience, the RAW processor doesn't correct hot pixels. When you import the RAW file in Lightroom, you can see them while the file loads and then the program corrects them. I didn't have the chance to check if the JPG files are pre-fixed by the camera (because my 550D doesn't have any hot pixels... yet) but it would something awesome to confirm. –  Andres Jun 9 '11 at 16:50
    
If you haven't seen any, than they are fixed. Every camera has hot pixels, this is different from a dead pixel on your LCD as they are temporary. –  Boris Jun 9 '11 at 17:57
    
I see dead pixels in videos all the time, on my Canon 5D II too. Not in my photos. –  Boris Jun 9 '11 at 17:57
show 1 more comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.