Taking Photos

[JimBo]

When a laser is scanning the beam is always at full power at any point, it is just that it is only at that point for a very short tie.
Have a look at the info on Bills Pangolin site for the explanation if you don't understand why.

Jim

[jkaiser3000]

I stand corrected .

Under those circumstances, the laser CAN damage the pixels, even if scanning :P

When a laser is scanning the beam is always at full power at any point

That applies to TTL I think. With analog, you can have less than full at any point. Sorry, I'm splitting hairs here :lol:

[buffo]

Actually, there is a difference.

Scanned beams can only irradiate the CCD for a brief period. A static beam will continuously cook the thing. So, depending on the power of the laser in question, you may or may not end up damaging the CCD with a scanned beam.

The information on the Pangolin site that Bill Brenner referenced in his other post deals with damage to the human retina. But the power limits are a lot lower for the human eye than they are for a CCD. Damage is a function of power level AND duration of exposure. It's just that because our eyes are *so* sensitive, it is possible to exceed the permissible exposure level and cause damage to our eyes even with a relatively modest-power-level laser and the shortest possible exposure based on the max scanner speed. (This is the main point Bill was trying to make - namely that you can NOT rely on fast scanning to protect your audience from eye damage, because even at medium power levels and fast scans, the total exposure is already high enough that you are in the danger zone.)

Some CCD's are no doubt very sensitive, but I have a 2.1 megapixel Fuji Finepix camera that has survived several direct shots (static beam for 2-3 seconds) from a 100 mw laser with no ill effects and no dead pixels. I woulnd't want to try the same trick with my eyes though!

Adam