MarkusQ 8 hours ago

And their advice is...don't point your camera at their cars?

What about traffic cameras? Or dash cams? Or other self driving cars that use cameras (exclusively, or in addition to their own lidar systems)? If you go around firing a laser powerful enough to damage other people's property in all directions, it would seem that the onus should be on you, not on whoever you zapped.

  • goku12 7 hours ago

    It appears that only cameras that take close up images of the sensor are affected (from the article). Traffic cams and dash cams are too far away to be affected (you can see this in the posted video itself). The self-driving cameras are wide-angle cameras and are not affected. Therefore, they don't really affect other people's property.

    And in case you really need to image it up close, the laser operates at NIR (1550 nm). Our eyes are insensitive above 700nm (which is why they don't damage our eyes), so there isn't any point in capturing that wavelength. You can safely filter it out with appropriate hardware filters, without any sort of loss in image quality.

    Now there is a question as to why the phone camera captures a wavelength that we don't see anyway. You can see this even with a regular TV remote (or anything similar with an IR emitter). You can't see the signal directly, but they turn up in captured videos with a purple hue. I haven't explored the technical reason for this. But my guess would be that the camera's internal red and blue filters have unwanted secondary transmission peaks at those wavelengths. So adding an extra wideband blocking filter at that wavelength to every camera by default is not a bad idea.

    Another thing about the camera that surprises me is that the sensor pixels can be saturated enough to damage it permanently. I think that these pixels are suffering a permanent stuck-at-1 failure here. Sensor saturation is a common phenomenon and results in washed out images. But this is the first time I'm seeing a permanent breakdown. (Also indicates how much I know (or not) about cameras.)

    And of course, the biggest question is what can be done with the Lidar optical power output. That is decided by the required signal-to-noise ratio of reflected light at the Lidar input, for an object at the maximum desired distance. There isn't much you can do here since that range is necessary for safety (so that dangers can be detected at far enough distances). Another parameter that can be changed is the laser wavelength. I don't know much about this either, but my guess is that it's limited by the solid state laser technology. I don't know how much freedom is available on that side.