r/explainlikeimfive • u/arztnur • 1d ago
Technology Eli5 How does a laser pointer affect a surveillance camera?
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u/crowediddly 1d ago
Any easily bought laser pointer will do absolutely nothing except create glare and obscure some of the picture while the laser is being shined.
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u/SoulWager 1d ago
You would hope, but sometimes the cheap laser pointers are way over their labeled power.
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u/dfmz 1d ago
Ok, let's clear things up a bit.
Run-of-the-mill, consumer-grade laser pointers will do jack shit to a quality sensor, aside from maybe causing the picture to bloom temporarily, only to recover after a few seconds. To do real, lasting harm, you'd need a rather powerful laser to begin with, ideally a green one (red is less effective at equal power) or an IR laser, especially a military-grade one (not normally sold to civilians), which would cause temporary blinding of the sensor and possibly permanent damage if sustained, which would require very precise collimation - think of the laser on a very, very stable, non-vibrating stand that is capable of holding its position to the millimeter over time.
Especially powerful lasers, like those sold by companies such as Wicked Lasers, would easily destroy the sensor, but they're hard to find nowadays, because they're incredibly dangerous to use (as are IR lasers), and the truly powerful ones are very expensive.
So yes, it's possible to obfuscate a camera sensor, but not with a standard laser pointer, at least not for more than a couple of seconds. The precision needed to keep the beam focused on the sensor long enough to destroy it isn't possible with a handheld device, period.
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u/CfaxAttax 1d ago
Imagine you're staring at a really bright light for a minute and then turn your head to look at something else.. There is a short delay before the bright "halo" of light dissipates and you can see clearly again. This is basically what is going on with a camera. The camera uses very sensitive light receptors to pick up changes in light and a normal laser pointer will temporarily blind those sensors in the same way. A stronger, higher powered laser, can actually burn out the individual receptors and permanently damage the image by causing the receptors responsible for specific pixels to fail and go dark.
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u/Arcticbuzz10 1d ago
Generally speaking, with "regular lasers", it does not - it's mostly a movies thing.
However, cameras are like your eyes - they concentrate light into a small area, then capture and process it. If that small area is flooded with too much light (e.g. you look at the sun, or a very strong laser points at a camera), it could become temporarily or permanently damaged.
Depending on how the light hits the sensor, whether it's focused on a few pixels are more spread out, it could actually burn (the photodiodes in) it, leaving an area that can't capture light anymore.
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u/Ninfyr 1d ago
Depending on the power of the laser pointer it might permanently burn the image sensor, but I wouldn't say that a typical laser pointer would do that.
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u/crowediddly 1d ago
I will explicitly say that a typical laser pointer will NOT do anything of the sort.
The type of laser that would damage a security camera would also be extraordinarily dangerous to human eyes, which is why they generally aren't available for purchase on the open consumer market.
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u/ml20s 1d ago
The type of laser that would damage a security camera would also be extraordinarily dangerous to human eyes, which is why they generally aren't available for purchase on the open consumer market.
At least in the US, any rando can just buy one. It is very, very easy to get into big trouble (i.e., eye or skin injury) with lasers.
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u/Not_an_okama 1d ago
Back in my school days, one of the other middle schools in our district that a bunch of my friends went to would send the 8th graders that took chinese to china for a week over one of the breaks. Basically everyone would come home woth high powered laser pointers every year. My friend was showing me how his was more powerfull then the one his sister got 3 years prior. His was capable of popping balloons if held on the same spot for a few seconds.
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u/iprobablybrokeit 1d ago
Sending 8th graders to China is wild.
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u/Not_an_okama 1d ago
Basically everyone had a parent attend as well, but we were also the rich school district, i was one of the poorer kids despite coming from an upper middle class family.
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u/SoulWager 1d ago
which is why they generally aren't available for purchase on the open consumer market.
They are though. And worse, cheap lasers are often way over their listed power level.
Amazon/Aliexpress don't care.
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u/Far-Drawing-4444 1d ago
If it's powerful enough, it fries the photosensor, effectively blinding the camera. Like how pointing a laser into your eye would "burn" your retina.
A weaker laser would just temporarily overwhelm the photosensor. Similar to how a very bright spotlight aimed at you at night "blinds" you until the light is turned off.
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u/SoulWager 1d ago
Can permanently damage the sensor without completely blinding it though. On laser-related youtube channels you'll sometimes see some discolored spots in the video from prior damage.
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u/therealdilbert 23h ago
as an example, https://www.youtube.com/shorts/U16ubxokBac
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u/Dickulture 22h ago
Yikes, that should be illegal to have unshielded laser blasting out frying eyes and camera.
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u/oregon_coastal 1d ago
Think of some lasers like a really focuaed beam of sunlight. If you point it at your eye, it burns it and blinds it.
Think if a camera as having a light sensor in it, much like you eye. It also has a lense, which focuses a wider band of light into a narrower frame, just like the lens of your eye.
Pointing the right type laser right at the camera has the same effect as looking directly at the sun and the sensor is damaged (blinded).