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Need replacement for camera for detecting laser-reflections.

lasermore

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Mar 2, 2019
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Cameras don't seem to be good at detecting laser-spots/reflections in their view-finder.
It ends up showing just as a spot, about the same as a big tree-leaf on the ground.
The human eye sees the intense reflection like INSANE/RIDICULOUS, but NOT the camera.
(In fact even the sun, which you can't even look at directly, just shows up as a spot in a camera, but I digress.)
I need to find a replacement sensor that will detect the intensity/brightness so that the location
of the laser spot/reflection is detectable in the sensor's view-finder. It needs to 'ignore' all the other shtuff (leaves, etc)
and highlight the bright laser reflection. (Many cameras aren't that great at color
either; many of them show the 532nm green spot showing up as basically just a white spot.)
Any ideas?
Again I find it crazy how intense my reflection is (barely safe to even look at), but the camera just sees it as
another leaf on the ground.
 



Encap

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There are no camera sensors even close to the capacity of human visual systems ability, so... .
Cameras are not eyes nor the human visual system--cameras are very inferior technology -- a camera is what it is and has the limitations it has.

The white spot is because the brightness of the laser is beyond the dynamic range the camera can handle. The dynamic range of a camera or sensor is a commonly used term to characterize the ability to measure and distinguish different levels of light. The correct expression would be “intra‐scene” dynamic range as one would compare different pixels or areas in one frame. At the upper limit, pixels appear to be white for every higher value of intensity (saturation), while pixels appear black at the lower limit and below. The eye can accommodate is about 30 stops of light 1,000,000,000 to 1 black to white while the newest and best modern camera sensors are capable of capturing 14-15 stops of light. Pretty impressive, but still no match for visual perception, which can ‘see’ an astonishing 30 stops! 1000X times better than the best cameras. A 30-stop scene is what we remember, not the 14 stops of the camera or smartphone screen. This is one of the reasons photographs don't do justice to our memories. See: https://jameslorentson.com/blog/2018/9/5/we-see-more-than-our-cameras-do

"While humen vision is not made up of pixels, human eyes can be thought of as having a lot more pixels than your camera and calculated to be about equlvilent to 574 million pixels"

The camera you're using is not appropriate for laser imaging. Laser light is emitted in an extremely narrow wavelength (determined by the type of laser you're using, i.e. HeNe or whatever). As such, you want to use a monochromatic camera to measure laser beam intensity. Color cameras have pixel grids where they alternate having red, green, and blue filters over them in order to produce a color image, and limited dynamic range this gives inaccurate renderings

Here are some cameras made for the purpose: https://www.ophiropt.com/laser--measurement/beam-profilers/products/Beam-Profiling/Camera-Profiling-with-BeamGage even with these you often need to attenuate the intensity/brightness and use neutral density filters to reduce the amount of photons hitting the sensor to between 1% and 10%.

Short answer--you can't --the camera is crap compared to your eyesight brightness and contrast sensing wise and other ways also.

Anyway attempted to explained the differences and why a little bit.

Maybe this guy will give you a better understanding--hope it helps:
 
Last edited:

barthchris

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There are no camera sensors even close to the capacity of human visual systems ability, so... .
Cameras are not eyes nor the human visual system--cameras are very inferior technology -- a camera is what it is and has the limitations it has.

The white spot is because the brightness of the laser is beyond the dynamic range the camera can handle. The dynamic range of a camera or sensor is a commonly used term to characterize the ability to measure and distinguish different levels of light. The correct expression would be “intra‐scene” dynamic range as one would compare different pixels or areas in one frame. At the upper limit, pixels appear to be white for every higher value of intensity (saturation), while pixels appear black at the lower limit and below. The eye can accommodate is about 30 stops of light 1,000,000,000 to 1 black to white while the newest and best modern camera sensors are capable of capturing 14-15 stops of light. Pretty impressive, but still no match for visual perception, which can ‘see’ an astonishing 30 stops! 1000X times better than the best cameras. A 30-stop scene is what we remember, not the 14 stops of the camera or smartphone screen. This is one of the reasons photographs don't do justice to our memories. See: https://jameslorentson.com/blog/2018/9/5/we-see-more-than-our-cameras-do

"While humen vision is not made up of pixels, human eyes can be thought of as having a lot more pixels than your camera and calculated to be about equlvilent to 574 million pixels"

The camera you're using is not appropriate for laser imaging. Laser light is emitted in an extremely narrow wavelength (determined by the type of laser you're using, i.e. HeNe or whatever). As such, you want to use a monochromatic camera to measure laser beam intensity. Color cameras have pixel grids where they alternate having red, green, and blue filters over them in order to produce a color image, and limited dynamic range this gives inaccurate renderings

Here are some cameras made for the purpose: https://www.ophiropt.com/laser--measurement/beam-profilers/products/Beam-Profiling/Camera-Profiling-with-BeamGage even with these you often need to attenuate the intensity/brightness and use neutral density filters to reduce the amount of photons hitting the sensor to between 1% and 10%.

Maybe this guy will give you a better understanding--hope it helps:

Great info! Not so much to do with lasers but I can think of one thing a camera can do better than us. Stare and collect photons during long exposure astrophotography shots. I'm amazed at how much my eyes are missing during 20-30sec exposures of the night sky with camera on a tripod.


I love this, need to be careful with lasers and cam sensors. https://www.diyphotography.net/man-says-laser-from-self-driving-car-nuked-his-sony-a7r-ii/
 

barthchris

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??? Your question was not about lasers other than indirectly. I was about you camera and your eyes and the differences.
My answer was as much about lasers as your camera/eyes question was.
You were looking for ideas about how you can make your camera see laser light they way your eyes see it.

Short answer--you can't --the camera is crap compared to your eyesight brightness and contrast sensing wise and other ways also if you like that better. lol

Anyway attempted to explained the differences and why a little bit.
I think you confused me for the op. I agree with everything you say and thought your post was great. The eyes 574 million pixel equivalent is amazing and something I can add to my bank of knowledge.

There are ways we can exploit cam sensors to do things that our eyes cant but few are laser-related. I will say "light painting" at night with long exposures and lasers can yield interesting effects but thats beyond the scope of this question.
 

Encap

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I think you confused me for the op. I agree with everything you say and thought your post was great. The eyes 574 million pixel equivalent is amazing and something I can add to my bank of knowledge.

There are ways we can exploit cam sensors to do things that our eyes cant but few are laser-related. I will say "light painting" at night with long exposures and lasers can yield interesting effects but thats beyond the scope of this question.
Opps, your right. Error post deleted -- answer post modified.

Good article on lasers and camera sensors.
 

lasermore

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To encap: Great information, especially the ophir 'pointer' [no pun intended]. :)
Ophir -- very useful specialized camera -- so far seems to be exactly what I need.
 




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