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felix_casio · Joined: 16 Jul 2006 Posts: 1781 Location: www.felixtm.com

Just decided to check my 5d2 for hot dad pixels and have them plenty. I've been shooting lots of video with this body and none on my other body the evidence is indisputable that video causes these little pixels to burn out.

http://www.felixtm.com/Other/Hardware-Tests/6904787_SV8fph#!i=1801444951&k=M3MR24S&lb=1&s=O

this is the full size
30 seconds, iso 200
the dead pixels dont show in video, only on long exposure images.

pjmorley · Joined: 15 Apr 2005 Posts: 3302

Am I right in thinking that you are saying...

You have two 5D Mk2 bodies

On one of them you shoot lots of video and this is the one with hot pixels after a long exposure but the hot pixels aren't apparent on video.

On the other you don't shoot video and on that body there are no hot pixels with long exposure.

Are there reports that this is a common occurrence on the 5D Mk2?

It's an interesting observation but I wouldn't say that this is indisputable evidence that it is caused by shooting video based on the information you have given.

My understanding is that this hot pixels are quite common for long exposures on many cameras, not just Canon and it is the reason why most cameras have a built in function to map out hot pixels on long exposures.

Do you have that function switched on in one camera but not the other?

felix_casio · Joined: 16 Jul 2006 Posts: 1781 Location: www.felixtm.com

correct. the photo only body had two hot pixels which were there since I bought it and no more have occurred since my purchase. This one had 3 noticeable ones to begin with and now there are many more over 50-70 easily spottable ones.

the 5d2 has a mapout function?
if the noise reduction is applied it will take them out along with much detail of the rest of the image as well making the image pasty and wont be acceptable in stock.

pjmorley · Joined: 15 Apr 2005 Posts: 3302

I don't know if it is specifically a map out function, perhaps more noise reduction as you say but you can make your own overlay by taking an equivalent length exposure with the lens cap on, invert the image then layer it on top of the original. I think setting the top layer to darken does the trick but you could try different settings.

felix_casio · Joined: 16 Jul 2006 Posts: 1781 Location: www.felixtm.com