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Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
just a quick question, is it possible to damage/burn a CCD in a camera by capturing really bright objects? I want to film power arks to a wood, and where the arc touches the (already burnt/carbonized) wood, is a bright spot which causes vertical stripe to show up on the camera. I just want to make sure this is safe because the camera's not mine. Thanks
Registered Member #546
Joined: Fri Feb 23 2007, 11:43PM
Location: Albuquerque, NM
Posts: 239
Yes, you can damage a CCD with too intense a light source...like the sun or a laser. I am working on a time lapse project and burned out a CCD from sun glare.
Arcs on the other hand probably wont permanently damage the device.
Also many newer camera have circuits built in to prevent CCD damage from intense light sources (i.e. they blank out when pointed at the sun)
Do the streaks you see just appear on the cameras LCD view finder, or are they in the actual image when viewed on a computer?
The LCDs they use on cameras are very cheap and don't have a very high Dmax (density range) and they really wig out when they get too much signal - you can probably ignore it.
_SOME_ cameras have a "zebra stripe" effect that you can turn on to show areas that will be over exposed... if you see even black stripes on bright areas that's probably what it is.
...
Anyways, if in doubt you can use a 5 or 6 stop neutral density filter - that will attenuate the arc's light to a "safe" level for the camera.
also keep in mind the light from an arc follows the same rule as all light, intensity decreases as the inverse square of the distance. The further away you are the less intense the light. Even with a large lens if you're 20-30 feet back, zoomed in a bit, you should be safer than being 5' away zoomed out wide... you know what I'm saying?
Anyways, good luck, and post arc pics here when you're done :)
Registered Member #180
Joined: Thu Feb 16 2006, 02:12AM
Location: Ontario, Canada
Posts: 187
I noticed the stripes on videos of my tesla coil. The spark gap, that was made of different heat sink peices and copper would create the streaks, there was one streak for every gap. I have no idea what causes it... Even when the camera was not pointing directly at the gap you could still see the lines, for instance if your field of view was anywhere above the gap.
Registered Member #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
CT2 wrote ...
I noticed the stripes on videos of my tesla coil. The spark gap, that was made of different heat sink peices and copper would create the streaks, there was one streak for every gap. I have no idea what causes it... Even when the camera was not pointing directly at the gap you could still see the lines, for instance if your field of view was anywhere above the gap.
Those stripes you see is what is called blooming. Its when charge from one pixel floods into an adjacent pixel and so forth . . . causing the stripes you see. This is typical of CCD sensors in which data is read out of each row in sequence as opposed to CMOS sensors which actually can read data from each pixel independently.
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Camera CCD question
, if you're interested 
