All good points Andy---I expect to see more legislation on this as well as manufacturers of Lasers being responsible to help ensure safety even more. Lasers are relatively new, especially in LiDAR. And there will always be idiots out there using laser pointers improperly and not for what they were intended. It's like hackers on the internet---they can do lots of damage and technology keeps trying to curb their hurtful actions, but it's a never-ending battle.
I'm not an expert on any of this. But I know that I fear lasers of almost any power level, and have for half a century. It's not an irrational fear. Lasers are fine if you know where they are pointed. Laser shows may freak me out, because the audience is in range and because there is a LOT more peak power in those than in a simple laser pointer to use on a whiteboard.
My understanding is that most tissue damage to the human body, happens because of heating (I'm an RF guy), so there is a time component to it, and very brief exposure (say, microseconds) tends to be safer. What matters is the total energy absorbed -- the area under the curve -- rather than the peak power level. Human bodies being what they are, heating over a period of time tends to spread out somewhat.
This is in contrast to a camera's pixel, which is a tiny speck that maybe could be wiped out in an instant, at an energy level (area under the curve) that is too small to heat up and damage living tissue.
re: DSLRs -- Any camera with an electronic viewfinder has the sensor always susceptible to damage. Any camera with an optical viewfinder has your eye susceptible to damage.
Interesting questions about using filters to reduce the damage potential. Of course that only works if the laser source is the same color or wavelength range that the filter is tuned to.
Steve, Nice blog and very appropriate references. It looks like the school physics learning of light, heat and electricity being separate chapters still haunts us despite the later EM wave knowledge. RF engineers have documented enough about the sensitive front end protections of all outdoor measurements with spectrum analysers and all RF receivers in the presence of (pulsed) radar transmitters or high power Rf transmitters.Pulsed lasers are like radar transmitter equivalents and will have to be treated with respect when camera imaging sensors are around. RF engineers also have popularised the dB notation but do we get to know the amount of attenuation of an equivalent optical filter with "broad enough optical band" attenuation? Can we buy say an optical smoke grey filter with a specified attenuation to solve this problem and this(https://www.nbcnews.com/news/africa/pentagon-accuses-chinese-blinding-djibouti-based-u-s-pilots-lasers-n871096 )?
Due to the recent proliferation of lasers and cameras especially in the last 25 years, we are seeing an increasing "Laser and Camera EMI" or should we say "OI"(optical Interference)? May be when self driving vehicles arrive on road, apart from digital cameras , even a low cost mobile phone camera will perhaps have a front end protection as a standsrd feature? But are the eyes of a spectacle wearing rider in such a car (waiting at a signal) still safe with the multiple lidar rays entering into his eyes?
Thanks for you comments/questions---let me clarify:
"A man using his new $1,198 Sony camera found that his photographs were damaged...". ---the camera CCD component was allegedly permanently damaged.
"The image below shows numerous laser-caused spots on an HP Photosmart 945, a 5-megapixel camera"----Sorry about that---I am adding the image to the above artilce now from this article http://www.laserpointersafety.com/ilda-camera-info.html
Good point about: But if you are on telephoto zoom and point your camera at a laser, that light is delivered directly, optically, to your eye, so be very careful! This won't happen if you're looking at a viewfinder on lesser cameras, even if the laser damages the sensor.
And thanks for catching the discrepancies and areas that needed clarification
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