Did I create these bad pixels?

[Doug Bennett]

We borrowed an XL1 last month to shoot a couple of scenes. The first few scenes we shot everything was fine. But the third week we noticed two dead pixels. They weren't there when we picked the camera up but they were when we took it back. We borrowed it from a friend and he's not blaming us - but I'm just wondering - is there anything we could have done to cause the problem, or is it just wear and tear?

[Nathan Gifford]

Well first I would be sure its not some kind of crud in the system. If its truly bad pixels, they sometimes can be remapped...that is if Canon still services the unit.

[Don Palomaki]

Factory service for the XL1 may not be available, it has been discontinued for more than 7 years.

Are they hot pixels (white spots) or dead pixels (dark spots)?

FWIW: hot pixels are most often encountered when shooting at very slow shutter speeds or with high gain under low light conditions with scenes with lots of shadow area. This condition caused by the dark current of the pixels.

[Doug Bennett]

The pixels are white. They become more visible as the camera warms up, and when gain is cranked up?

Is there anything we may have done to cause them? Or is it just age/wear & tear?

Thanks

[Don Palomaki]

Pixel dark current does increase with temperature.

It is possible that some radiation exposure may have effected a pixel, more likely at high altitudes though.

[Doug Bennett]

Don, you mean radiation from the sun? One morning we were shooting outside at altititude - 8-10,000 feet

[Brendan Donohue]

check out digital heaven's reincarnation plugin for FCP...it masks up to 2 dead pixels at a time: http://www.dvinfo.net/conf/showthrea...digital+heaven

dead pixels on the CCD's are pretty common with canons..I've had 3 GL1s in my possesion and they've all developed or had hot/dead pixels..I've heard that pointing the camera directly at the sun can cause this problem, but I don't know how true that is, it seems feasible though

[Doug Bennett]

thanks Brendan - fixing the problem is not really the issue, I just wanted to know whether I should offer compensation. We ending up buying the camera for a price everyone was happy with.

[Don Palomaki]

At high altitude there is more cosmic radiation (gamma rays and other sub atomic particle stuff flying about in space, not just what we think of as sun shine (visible light) that is no filtered by the aitmosphere), and too much of that can trigger a hot pixel.