digital imaging question

[powertool]

How bright does a source need to be to overexpose a CCD, or wash-out the image produced on a digital camera? For the purposes of this discussion assume the camera is a quality consumer grade piece, scene being captured is a wide field directly lit by daylight, and exposure settings are "automatic" or determined by the camera. Please note any assumptions you must make to answer the question.
I'm not looking to wash-out the entire image, only a localized object within the field being photographed.

Thanks.

 

[ElectronGuru]

There are three concerns here:

1) caution: don't put retina searing light into the camera

2) to make sure you 'capture' enough light to make a photo without capturing to much, take a picture then check the camera's histogram. Any curve gets cut off along the top is overexposed (aka, clipped).

3) once you get the image into the computer, make sure it is not brightened further. Pixels that are already pure white won't get any whiter and pixels that are near white will be 'squished' into the same color (becoming inaccurate).

If your camera records RAW, software will often warn you on import (like with a red color) when colors are to bright or to dark. You can also reduce the exposure of a given image retroactively to fix such images.

and :welcome:

 

[blasterman]

How bright does a source need to be to overexpose a CCD, or wash-out the image produced on a digital camera?

How long is a piece of string?

It's not a question of brightness, but contrast range. Even a crappy digital camera can expose a polar bear on a glacier at high noon during a solar flare. You just reduce exposure.

It's about a 9-10stop range with most digital cameras. RAW gives you a bit more lattitude my scraping those nth bits out to give a tad more tonal graduation.

If you're looking to blow out highlights on purpose, then it's easier if you adjust the in camera settings to pump up contrast a bit. Or, just stroke the curve in Photoshop.

 

[powertool]

I don't have any control over the camera. I'm trying to blast something in order to prevent it from being photographed.