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If it can do that to a camera, what's it doing to eyes? edit: > "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally,

If it can do that to a camera, what's it doing to eyes? edit: > "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." - I'm still not entirely sold.

jpalomaki 8y ago
From the article "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." Another site claims "However, there are no MPEs for sensors such as CMOS or CCD chips. This means a show may be perfectly safe for eyes, but could possibly damage a camera sensor. One reason is that camera lenses may gather more laser light, and concentrate it to a finer point. Another reason is that CMOS or CCD sensors are more easily damaged than the eye."[1] [1] http://www.laserpointersafety.com/ilda-camera-info.html http://www.laserpointersafety.com/ilda-camera-info.html
- BuildTheRobots 8y ago
  I'd love to see some independent results from someone who doesn't have skin in the game. Whilst damage might be more obvious in a camera CCD, even small amounts of cumulative damage over time could be doing serious harm without it being immediately obvious. I've seen f/1.6 lenses, where as the eyes are apparently f/8.3 - f/2.2, so yes the eyes take in less light, but it's substantially harder than an EF-S mount to swapout. edit: also, what about animals with good night vision? they are more sensitive and take in more light - are they at danger?
ddebernardy 8y ago
The article actually has the answer: > Other lidar makers use lasers with a wavelength of 1550nm. This tends to be more expensive because sensors have to be made out of exotic materials like indium-gallium arsenide rather than silicon. But it also has a big advantage: the fluid in the human eye is opaque to 1550nm light, so the light can't reach the retina at the back of the eye. This means lasers can operate at much higher power levels without posing an eye safety risk.
- BuildTheRobots 8y ago
  > the fluid in the human eye is opaque to 1550nm light sure, but does this hold true for most land-based animals and birds? How much range does this give us? reflections can shift by half a wavelength - is that still opaque too? I'm not saying this isn't safe, but suddenly having a tonne of high power laser sources pointing everywhere at all times might actually have some consequences still...
  - csours 8y ago
    Mammals, lizards, amphibians, and birds all have water-based eyes, but I wonder what this would do to insects.
  - jerf 8y ago
    If I am reading the chart labelled "The visible and UV spectra of liquid water" at http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html (about 2/3rds down the page) correctly, water is fairly opaque at 1550nm. If my hurried wikipedia education on the topic is correct, that chart is saying it's quite opaque at that frequency, even at bat eyeball scales. Corrections welcomed from people with more training in this field. (I'm not sure I'm not getting some crossed units when I tried to resolve that into numbers normals like me would understand; is that really 1/e^1000 transmitted per centimeter travelled? e^1000 is a big number. There's even bigger ones on that chart. Then again, if a two-atom-thick layer of gold is enough to make something look like gold and completely obscure what's underneath, I guess that might make sense and my intuition is just off, because when I convert that into this sort of scheme I get big numbers there, too.)
    - ddebernardy 8y ago
      If memory serves me well, water absorbs that wavelength, so it would basically function sort of like a microwave oven, but with such a much lower energy level that you can basically ignore it.
      - 8y ago
apendleton 8y ago
They address in the article that the frequency they're using can't damage the retina because the fluid in the eye is opaque to light at this frequency.
icelancer 8y ago
A camera is not the human eye. Just because they are both technically optical sensors does not mean they are equivalent really at all.

jpalomaki 8y ago

From the article "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." Another site claims "However, there are no MPEs for sensors such as CMOS or CCD chips. This means a show may be perfectly safe for eyes, but could possibly damage a camera sensor. One reason is that camera lenses may gather more laser light, and concentrate it to a finer point. Another reason is that CMOS or CCD sensors are more easily damaged than the eye."[1] [1] http://www.laserpointersafety.com/ilda-camera-info.html http://www.laserpointersafety.com/ilda-camera-info.html

BuildTheRobots 8y ago
I'd love to see some independent results from someone who doesn't have skin in the game. Whilst damage might be more obvious in a camera CCD, even small amounts of cumulative damage over time could be doing serious harm without it being immediately obvious. I've seen f/1.6 lenses, where as the eyes are apparently f/8.3 - f/2.2, so yes the eyes take in less light, but it's substantially harder than an EF-S mount to swapout. edit: also, what about animals with good night vision? they are more sensitive and take in more light - are they at danger?

ddebernardy 8y ago

The article actually has the answer: > Other lidar makers use lasers with a wavelength of 1550nm. This tends to be more expensive because sensors have to be made out of exotic materials like indium-gallium arsenide rather than silicon. But it also has a big advantage: the fluid in the human eye is opaque to 1550nm light, so the light can't reach the retina at the back of the eye. This means lasers can operate at much higher power levels without posing an eye safety risk.

BuildTheRobots 8y ago
> the fluid in the human eye is opaque to 1550nm light sure, but does this hold true for most land-based animals and birds? How much range does this give us? reflections can shift by half a wavelength - is that still opaque too? I'm not saying this isn't safe, but suddenly having a tonne of high power laser sources pointing everywhere at all times might actually have some consequences still...
- csours 8y ago
  Mammals, lizards, amphibians, and birds all have water-based eyes, but I wonder what this would do to insects.
- jerf 8y ago
  If I am reading the chart labelled "The visible and UV spectra of liquid water" at http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html (about 2/3rds down the page) correctly, water is fairly opaque at 1550nm. If my hurried wikipedia education on the topic is correct, that chart is saying it's quite opaque at that frequency, even at bat eyeball scales. Corrections welcomed from people with more training in this field. (I'm not sure I'm not getting some crossed units when I tried to resolve that into numbers normals like me would understand; is that really 1/e^1000 transmitted per centimeter travelled? e^1000 is a big number. There's even bigger ones on that chart. Then again, if a two-atom-thick layer of gold is enough to make something look like gold and completely obscure what's underneath, I guess that might make sense and my intuition is just off, because when I convert that into this sort of scheme I get big numbers there, too.)
  - ddebernardy 8y ago
    If memory serves me well, water absorbs that wavelength, so it would basically function sort of like a microwave oven, but with such a much lower energy level that you can basically ignore it.
    - 8y ago

apendleton 8y ago

They address in the article that the frequency they're using can't damage the retina because the fluid in the eye is opaque to light at this frequency.

icelancer 8y ago

A camera is not the human eye. Just because they are both technically optical sensors does not mean they are equivalent really at all.