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Industry News: Sony officially warns about CIS laser damage
- Thread starter Canon Rumors Guy
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somebody please help me out here, what is a CIS laser?
Funny I need to ask, because I honestly am a senior laser physicist and semiconductor scientist and I've never heard the term. I can only imagine these are class 4 lasers used for light shows?... but the terminology, seriously, never heard of it.
As to laser damaging thresholds of imaging sensors, yes, I'm well aware. For high power beams in the lab I've never had an issue though. I either use a laser filter (to block that wavelength) if I want to observe the plasma of something irradiated by laser for instance or, I use a second grade camera, maybe a small aperture and higher ISO. What I never would do is scan a laser beam across the lens just like I wouldn't do that with my eyes so in my use cases whenever I'd like to take an awesome photo/video of some laser process, I usually photograph something else irradiated by the laser beam (and thus scattering off it) or the beam itself scattering in air or I filter out the laser's wavelength altogether.
So not knowing what these folks are talking about (CIS). Nothing helps but less light. Higher shutter speed obviously only helps when using film
Funny I need to ask, because I honestly am a senior laser physicist and semiconductor scientist and I've never heard the term. I can only imagine these are class 4 lasers used for light shows?... but the terminology, seriously, never heard of it.
As to laser damaging thresholds of imaging sensors, yes, I'm well aware. For high power beams in the lab I've never had an issue though. I either use a laser filter (to block that wavelength) if I want to observe the plasma of something irradiated by laser for instance or, I use a second grade camera, maybe a small aperture and higher ISO. What I never would do is scan a laser beam across the lens just like I wouldn't do that with my eyes so in my use cases whenever I'd like to take an awesome photo/video of some laser process, I usually photograph something else irradiated by the laser beam (and thus scattering off it) or the beam itself scattering in air or I filter out the laser's wavelength altogether.
So not knowing what these folks are talking about (CIS). Nothing helps but less light. Higher shutter speed obviously only helps when using film
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haha...ok, thx.
Now that terminology is an unnecessary constraint then. The sensor's size does not matter when it comes to laser damage. All that matters is the damaging threshold as a function of intensity, wavelength and sensor material (and short pulsed lasers will kill off the sensors even faster but nobody should use pulsed lasers for filming or photography who has no clue about what they're doing)
Maybe that is why I didn't even think twice about CIS having to be some sort of laser type (that I'm unfamiliar with). Any class four laser can damage a sensor. The better (sharper) the lens, the higher the probability of the damage ;-)
Now that terminology is an unnecessary constraint then. The sensor's size does not matter when it comes to laser damage. All that matters is the damaging threshold as a function of intensity, wavelength and sensor material (and short pulsed lasers will kill off the sensors even faster but nobody should use pulsed lasers for filming or photography who has no clue about what they're doing)
Maybe that is why I didn't even think twice about CIS having to be some sort of laser type (that I'm unfamiliar with). Any class four laser can damage a sensor. The better (sharper) the lens, the higher the probability of the damage ;-)
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Even without lasers I don't think that it is a good idea that the sensor is exposed to light all the time if the camera is turned on. With a DSLR you can shoot 1,000 photos with an exposure of 1/200 second each and the sensor will only be exposed for 5 seconds combined. Powering the sensor all the time will warm it up an increase noise and it might also make hot pixels more likely. With my DSLR I even felt bad when I made a short video, because that single video used more sensor time than thousands of photos at daytime.
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1) I do not think that is what is going on here. People are using cameras in places that have lasers.
2) There are remote focus systems that use LIDAR but I have never heard of this happening with them.
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It's the total energy in the light. UV short wavelength light is more energetic than IR. (so violet lasers need more care) For the same apparent brightness, green lasers are safer simply because we see green better so a less powerful laser 'looks' as bright.
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I am just linking this article for the embedded YouTube videos which show the damage happening in real-time,
ymcinema.com
Sony Says: “Do not directly expose the lens to laser beams” - YMCinema - News & Insights on Digital Cinema
Sony has officially published a warning regarding laser damage when the sensor is directly exposed to a laser beam. Although it’s obvious, not many are familiar that a laser beam can destroy your camera sensor. Even if it’s cool, you should avoid shooting between lasers. Read on to understand...
ymcinema.com
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true, but you're constructing a scenario that isn't real, IMHO.
First of all, if the radiation is strong enough to damage the sensor, it sure as hell would damage your retina looking through the viewfinder. Secondly, good DSLM like my R5 have a proper mechanical shutter that is closed when the camera is shut down, problem solved. The only real advantage is when turned off without lens-cap while looking towards the sun (or a strong (!) laser), the DSLR will just pass most of the energy through the viewfinder and out the back while the shutter curtain of the mirrorless will absorb at least all the visible light (since it's black) and heat up... possibly beyond the point of permanent damage (not sure about the IR reflectance, if they're smart, it's IR reflective).
So there is no damage threshold advantage of the DSLR over the mirrorless while using them. If you are using your camera in situations with lasers >class3, I'd much rather have that laser damage the sensor than my eye!... at least that's my opinion ;-)
1) yes, I get that. Some laser show which is probably running way above legal laser safety specs... otherwise it wouldn't harm a silicon chip
2) the strength of the LIDAR beams is also covered by laser safety regulations. On top of that, the lidar scans as fast as the mechanics and electronics provide, rotating for example. On top of that, the laser dots for LIDAR are usually divergent so they have a certain size. nobody wants super small dots everywhere, it's much more robust if they're larger. Therefore, the intensity is much smaller than with an ordinary laser pointer.
On top of that, a LIDAR usually works in the infrared so that humans won't see the dots/lines... it would drive us all insane otherwise. In the infrared, the optical absorption depth in silicon chips is much longer meaning that the "energy per volume" is smaller in an imaging chip. Also the overall quantum efficiency is smaller meaning less of the infrared photons even cause a signal. More importantly though, almost all camera sensors for RGB (colored) image acquisition have an infrared blocking filter (usually reflecting IR away) so that images look familiar to how we see things. Therefore, an IR laser is unlikely to cause damage to the sensor!! Obviously though the sensors detecting the LIDAR don't have those filters, they might in fact have the opposite, a filter that only lets light of the IR LIDAR wavelength pass so they ONLY see the dots projected and such.
two things:
first of all you're right, the energy of UV photons is higher than that of IR but that's not the reason the intensity threshold for damaging silicon based imaging chips or photodiodes is much lower in the UV. It's the absorption depth. UV photons get absorbed within <20nm (nanometers) whilst IR photons penetrate hundreds of micrometers or millimeters (depending on the wavelength) into the silicon before being absorbed. Thus, the energy per volume is much higher on the surface of the silicon chip when irradiated with UV.
You're right but also wrong on perceived brightness and deducting danger from that. At the same power, blue/violet and red lasers seems dimmer than green. True UV and IR lasers can't be seen by us directly but you might see some glow from luminescense or fluorescence... something like a black light effect. However IR lasers are even more dangerous than UV ones for the fact that UV lasers primarily won't damage your retina but the cornea or lens. IR lasers usually are more powerful and totally invisible (no fluorescense without special materials).
Bottom line. All visible lasers are a bit safer because people can see them and your eye/iris actually reacts, you blink, shut your eye, look away. Outside the visible spectrum, none of that happens. Then again... if the laser is strong, your reaction time is MUCH too small to prevent damage to your eye, so NO LASER WAVELENGTH is safer than the other if the power is too high ;-)
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One article said that image sensors are 1000 times as sensible to lasers than the human eye. And if the laser is in focus, it is exactly focussed on a tiny part of the sensor and will cause maximum damage there.
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really? hm...
Please specify what you mean by "sensible" - I don't understand what you mean by that ... the sensors surely have no feelings?! ;-)
If you mean "sensitive" as in damageable then I'd like to see that article. As a matter of fact, I'm an expert on laser <-> silicon interaction and damage thresholds and I would LOVE to see this as I do not believe that to be the case.
If you mean "sensitive" as in good receivers: Image sensors are certainly NOT 1000x more sensitive to detect laser-photons in the visible spectrum compared to (good) human eyes. image sensors can detect the lasers much better (that's true for certain wavelengths outside the human visible spectrum but in the visible spectrum, the human eye can also detect single photons in the best case).
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One thing to remember. Some lenses have a MUCH larger aperture than a human eye. Therefore sure, if I widen a laserbeam to 50mm diameter AND a lens actually has that aperture, the focused spot will have 100 times the intensity compared to the same laser beam irradiating my face (with a 5mm pupil diameter). So in that sense, the optical systems, especially of large aperture lenses can focus a lot more laser power when collecting larger/divergent laser beams. So for show lasers, the intensity (power per area) is often limited by widening the beams. This does NOT mean,that silicon sensory can't take much higher intensity than the human eye (because they definitely can) BUT, depending on the lens in front of them, they'll be irradiated by MUCH higher intensity in the first place.
What helps against lasers --> less intense light!
That's why I stated above: close that aperture, thus bump the ISO!
A class 1 laser(pointer) will not damage your camera, no matter the lens, regardless of color/wavelength.
I guarantee it!
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This really reads like the lawyers reviewed the press release copy. The folks who operate laser light shows are using lasers with sufficiently high output to damage the sensor in your camera. That's it. Don't expose your camera to the laser beams, because it will damage them.
That the FDA allows such high power lasers (the ao-called professional models are over a watt, which is crazy when peoples eyes can actually be exposed to them) seems a bit questionable to me. They are apparently counting on the fact that the beams sweep by very fast. The fact that camera sensors get damaged seems to suggest that it might not be such a good idea for peoples eyes either.
That the FDA allows such high power lasers (the ao-called professional models are over a watt, which is crazy when peoples eyes can actually be exposed to them) seems a bit questionable to me. They are apparently counting on the fact that the beams sweep by very fast. The fact that camera sensors get damaged seems to suggest that it might not be such a good idea for peoples eyes either.
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That 1000x figure comes from the article posted one page ago: https://petapixel.com/2019/01/12/mans-1998-mirrorless-camera-fried-by-self-driving-car-laser
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I just had a read and it seems that in the US all this craziness shown in videos is legal in the US for instance. For shows 100W+ lasers are apparently legal to be pointed INTO crowds, ridiculous! All of that is ILLEGAL in the EU! Here, the angle-space must be limited in such a way that the laser can never reach the crowd and thus not point into their faces/eyes.
The statement from the LIDAR (AEye) CEO Luis Dussan is total BS!
"his company’s lidars are completely safe for human eyes but didn’t deny that they are capable of damaging camera sensors". From what I gather, they use 1550nm IR lasers. Silicon is transparent at that wavelength, but not the metal layers or maybe the bayer matrix filters, so heat will be generated, yes. Absorption in water is high thus the retina of your eye might be save, but not the cornea and lens.
And even if the beams are eye-safe.. what if somebody looks at a car through some binoculars? Whoever approved this is clueless and belongs in prison IMHO.
Bottom line. I think the US and other countries are crazy careless regarding laser safety regulations. I cannot fathom how it can be legal to direct those show lasers INTO the crowd... speechless. Good to know, I shall never attend a US-based laser-show.
The statement from the LIDAR (AEye) CEO Luis Dussan is total BS!
"his company’s lidars are completely safe for human eyes but didn’t deny that they are capable of damaging camera sensors". From what I gather, they use 1550nm IR lasers. Silicon is transparent at that wavelength, but not the metal layers or maybe the bayer matrix filters, so heat will be generated, yes. Absorption in water is high thus the retina of your eye might be save, but not the cornea and lens.
And even if the beams are eye-safe.. what if somebody looks at a car through some binoculars? Whoever approved this is clueless and belongs in prison IMHO.
Bottom line. I think the US and other countries are crazy careless regarding laser safety regulations. I cannot fathom how it can be legal to direct those show lasers INTO the crowd... speechless. Good to know, I shall never attend a US-based laser-show.
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This is mainly a mirrorless camera problem because of the length of time the sensor remains exposed - which is basically all the time you have the EVF or Live View active. DSLR sensor obviously can be at risk as well in Live View, but far lower risk via OVF since sensor is only exposed for a fraction of a second instead of continuously.
Sony likely made this statement to cement future warranty claim denials.
Sony likely made this statement to cement future warranty claim denials.
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