View Full Version : Burn out CCD's from overexposure?


Scott Jaco
October 7th, 2007, 08:02 PM
Hi,

I have been running my iris in manual and since I do wedding shoots, I'm constantly inside, outside and everything in between. When I walk outside, the first thing I have to do is close the iris a bit.

I wanted to know if oversaturating the iris producing a completely white screen is hard on the CCD's. My guess is that it's not, since I've never heard anyone talk about it.

Just curious.

Adam Oas
October 8th, 2007, 03:10 PM
I don't believe so, it's probably not recommended but you can get shots of the sun with most cameras nowadays, and that's a LOT more light striking the CCD than the circumstance you're describing.

Scott Jaco
October 10th, 2007, 03:18 AM
Yah,

I figured, if you can take the lens off in broad daylight, I can't see how having the iris set too hot is a bad thing.

My understanding is that the CCD produces a maximum voltage which translates to an all white picture but once it reaches 100%, that is it.

In otherwords, you can't burn out the CCD's from overexposure.

Paul Jefferies
October 10th, 2007, 05:54 AM
you can't burn out the CCD's from overexposure.
Maybe not, but would pointing it directly at the sun and opening the lens up turn the lens into a giant magnifying glass, focusing all the sun's heat onto the CCD, and thereby increase the temperature on the CCD greatly, possibly enough to cause harm on a long shot?

Ben Lynn
October 12th, 2007, 06:40 PM
You're right about the ccds Scott. They hit 100% and that's it, they won't burn out from overexposure. If you use the knee function it can limit that down even a bit more so that it doesn't clip out at such a high level.

Paul, run a test on that one and report back on the results. If you're camera blows out a ccd then we know that you were right. If it survives then we'll know that your theory is wrong.

Ok, seriously Paul, don't run a test : ) I've had sun shots for short periods of time, 3-5 seconds on a pan down or across, but I wouldn't want to keep the camera pointed at the sun. I would have to think that your idea is right and it would heat damage the ccd very quickly. Let's hope no one ever puts that to the test and ends up blowing some ccds.

Ben

Chris Hurd
October 12th, 2007, 10:04 PM
Thread title changed from "Here's a stupid question" to "burn out CCD's from overexposure?" Please avoid ambiguous thread titles. Thanks in advance,

Dave Beaty
October 14th, 2007, 10:55 AM
While walking outside with a wide open lens for a few minutes would not worry me, we did permantly damaged a CCD block by shooting timelapse images of the sun. So it can be done on a lock down shot.

On the same note, shooting lasers for medical procedures is also to be avoided at all costs without a protective filter. (same reason they make you wear goggles)

We shoot medical programming and ruined a D-35 shooting a skin resurfacing procedure hand held. The damage occurred from reflected laser light, not pointing the laser into the camera. Actually happened while taping.

But for normal use, I wouldn't worry. It's not like the old tube days.

Dave Beaty

Jad Meouchy
October 24th, 2007, 03:17 PM
What about shooting welders?

I've done several times without any noticeable problems

Dave Beaty
October 25th, 2007, 05:28 AM
As for ARC welders, I would avoid a lock down shot where the arc is stationary for a long time. As long as it's moving around I would predict it wouldn't hurt. But if it can burn your retinas, it probably can burn the CCD chips. Perhaps the 1/3 chips are more suseptable to this. I've never heard of a 2/3 camera being burned by shooting the sun in timelapse.

That said, I never thought the reflected light emitted by the skin laser could destroy the CCD block of a camera. The shot was of someones face, hand held with the light pulsing onto the skin as the surgeon moves it around. In about 2 secs a blackish oblong hole appears in the frame.