How does bright light hurt a CCD?

[Karen Love 0]

Hey guys,

My owners manual on a couple of my cameras mention not to expose them to bright light as it could harm the CCD. I have cameras that at some point of the day have the full sun staring right into the lens. At night, car headlights stare in to the lens. I can't imagine how I could avoid it? They mention "smearing" may result...what's "smearing".

 

Thanks a bunch,

Karen

[Karen Love 0]

oops, I forgot I had a signature already so signed it twice

[Scruit 0]

I'm not a professional, just a home user.

 

Avoiding direct sun can be a case of trial and error. Even if your camera is facing downwards, all it takes is a puddle on the ground at the right time of day and the sun can be reflected directly into the camera.

 

The experts here can tell you better than I can, but I can tell you that my experience is that no apparent long-term damage has resulted from headlights shining directly into any of my cameras.

 

The sun is another matter. I have a camera in my car that looks out the windshield and the sun is unavoidable. I have used an auto-iris lens to let the camera reduce the light coming in, and I'm about to add a UV/IR filter. I cannot comment on long-term effects, but my instance it that it's not good to intentionally point right at the sun at midday.

 

Also, it should be mentioned that if the sun is directly in shot then you image is probably going to be useless as the camera struggles to compensate, if it even can.

[Karen Love 0]

Thanks!

 

I have auto iris on a my cameras and the pictures look good (actually very good). I have the camera in a housing but there is not much of an overhang. The sun really hits it heavy in the evening when the sun is just starting to set.

[kensplace 0]

Smearing is when the light is too bright for the ccd sensor to handle it, it overloads the column of pixels and you get a bright line going down the screen - instead of what you really need to see.

[phred 0]

If you have ever used a magnifying glass to focus the sun on a piece of

paper you will understand the problem. The damage to the CCD is usually

caused by excessive heat build up as the lens focuses the sun on the CCD.

I have tested some CCDs to destruction in a lab setup, usually they just

stop working but just a few have exploded

 

You really should do all you can to avoid pointing your camera at the sun.

Reflected sunlight and car headlights are less of a worry - they just tend to ruin the image.

 

 

Smearing is... as Kensplace says..

 

 

Google 'CCD smearing' you should find some examples.

[Scruit 0]

Here's an extreme example of smearing from my car camera before the auto-iris lens. The white vertical line is the smear. This image was take at midday on a clear day in full sun - yet the image is useless.

 

 

After installing an auto-iris lens the smearing went away, although the image is still heavily impacted by the sun - the the image around the sun is at least usable.

[jisaac 0]

if you have your camera mounted reasonable high and not looking at the horizon then you should be ok. a puddle wont hurt it either. just don have it staring at the sun directly for any extended period of time.

[rory 0]

What Issac said, dont point it up at the sun .. you dont need to record whats going on the sky normally

[marzsit 0]

an ai lens adds a bit of a safety factor here, as just about every ai lens i've inspected has the ability to completely close it's iris supposedly as a camera self-protection scheme. we did ruin one of our ccd cameras at work that was fitted with a fixed iris... it was accidental, an engineer moved one of the arc welding stations from one side of the plant to the other, we had a camera set up to watch a polishing tumbler for overflowing in that spot. about a week of production welding later, and the camera just quit working...

[Karen Love 0]

Thanks Guys! wow, I appreciate the responses. I guess I was thinking no matter what you do with an outside camera on a full sun day the camera would be getting "full sun". I guess that's different then looking right into the sun though.

[rory 0]

I live in the Bahamas, we have lots of strong sun, I only had one camera lens go bad after 5 years from possible damage from looking in the direction of the Sunset everyday .. camera still worked and lens replaced. I wouldnt worry, just dont point it up at the sky.

 

However one thing to note, on cheap generic Cameras it more likely for the CCD to go quicker than a higher quality CCD, those $50 bullet cameras seem to get a horrible image after a year, but they still work.

Edited April 8, 2007 by Guest

[atropine 0]

If you have ever used a magnifying glass to focus the sun on a piece of

paper you will understand the problem. The damage to the CCD is usually

caused by excessive heat build up as the lens focuses the sun on the CCD.

Reflected sunlight and car headlights are less of a worry - they just tend to ruin the image.

 

 

so that is the real reason, it's heat from infra red, associated with light that is the problem. What about day/night cameras on night setting? And video cameras that have night function. Their manuals will complain about the nigh setting and bright light sources in addition to the bright light source warning in normal use.

 

Is there an additional problem not related to focussed infra red light that can physically damage CCD's? Can excess light alone in night mode cause the CCD heat up to the point of damage not due to incoming infra red but from the CCD itself overvoltaging and overheating it'self?

 

I have 3 old sony camcorders with super night shot (night shot with auto shutter speed that goes down to 1/6th of a second) which I was thinking of using as security cameras for 24 hour use. Anyway unlike professional security cameras there's no way of switching between day and night modes, so I"d have to keep it in night mode . Would you image as long as I make sure the sun doesn't hit the lens the camera will function without dying?

[phred 0]

Excess light alone should not cause overheating by the mechanism you

describe ie 'overvolting'

CCDs have a very sharp cutoff in response beyond which additional light

will not increase the output. The excess light will however cause additional

heating as visible light is absorbed by many materials and becomes IR

(quantum mechanics). It is actually pretty difficult to get rid of all IR

without cooling the CCD.

 

 

There are many different designs of CCD and some can tolerate more

heat than others. Those with microlenses and filters made of plastics, for

example, are more easily damaged by overexposure.

 

 

The problem with using your video cameras is that they have not been

designed for 24/7 use and the CCDs will not be designed with longterm

overexposure in mind. I also suspect they may suffer from image burn as

a result of viewing the same scene for long periods.

 

 

(good questions btw )

[atropine 0]

Thanks for the reply. Those camcorders arent' worth much these days. Old 1/4inch min dv cameras. Still no point in destroying them on a use they're not designed for. I"ll ebay them to raise some funds towards a real day/night security camera.

[phred 0]

Good idea

 

regards

[videobruce 0]

I have four Panasonic WV232/242 series of cameras and all of them have burns. One is from white garage doors that gets sunlight for a few hours, another is from a white railing that never received any sunlight at all (it was under a porch). Orginally all had manual iris lenses and the cameras were set to use the shutter. All of those leneses were replaced with auto-iris lenses, but the burn is still there. The one with the burn from the railing is in another location, but the 'burn' never went away.