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FrozenGate by Avery

Night vision goggles...?

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Shammikaze

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So, I somehow stumbled upon this video on YouTube and now I'm really curious...

Heres the question:
-Would this really work or is the guy full of it?

Link:  http://www.youtube.com/watch?v=GVr1KxQC6vI


Thoughts, comments, input, or science behind it would be appreciated... I feel like I might make a pair if it could work...

Thanks,
-Shammi
 





Shammikaze said:
So, I somehow stumbled upon this video on YouTube and now I'm really curious...

Heres the question:
-Would this really work or is the guy full of it?

Link:  http://www.youtube.com/watch?v=GVr1KxQC6vI


Thoughts, comments, input, or science behind it would be appreciated...  I feel like I might make a pair if it could work...

Thanks,
-Shammi
Click to expand...

No I say that would not work.

Its colour filter gel, how can that you see IR, it can't I say.

The reason you can see the IR when he shows it outside is cause video camera's CAN.
 
See, that's what I was thinking too, but at the same time it's also possible that his camera can't really pick it up, and that they do work.

Another question - what's stopping the IR LED from harming other peoples' vision? I assume it's IR in the safe range?

Thanks
-Shammi
 
So some of the folk on Something Awful were making believable but entirely false DIY guides kind of like what Kipkay was making. Pretty hilarious stuff really. I doubt this is from those people, but it's probably just as ridiculous.
 
Shammikaze said:
See, that's what I was thinking too, but at the same time it's also possible that his camera can't really pick it up, and that they do work.

[highlight]Another question - what's stopping the IR LED from harming other peoples' vision?  I assume it's IR in the safe range?[/highlight]

Thanks
-Shammi
Click to expand...
Normal infrared light isn't dangerous (unless, of course, it's high powered and you stare at it too long). Light from an LED is like light from a lightbulb, it's sporadic. Laser light is coherent meaning the photons all travel in the same direction. This gives the light a highly concentrated energy that is dangerous to the eyes :P
 
You can't see the IR light generated by those LEDs - it does work on cameras since the image sensors can pick up the longer wavelength light. So the glasses at night thing is a load of BS, but not so much for the other people selling magic "xray glasses" on ebay and such.

It works since you can see some near-IR in say the 700-750nm range which can sometimes pass through objects that are dark to visible light. So it sort of gives you a pseudo-xray vision, but it also dilates your pupils causing you to take in a ton of IR light since you only see a bit of it and the eyes try to compensate by opening wider.

Basically the whole idea is gimmicky and somewhat bad for your eyes. BUT, image sensors can see IR just fine and you can make a basic nightvision system with a camera and IR leds.
 
I think that the glasses shown on the video won't work at all. I've seen this before, but in a bit different setup. I do not see the point of the filters when you are going to use these in the dark anyway.. The idea is to block out all light that has not passed through the filters, so that your eyes will accommodate to the darkness. This accommodation is said to shift/extend your eyes sensitivity to NIR.(umm, checked this and it seems to do exactly the opposite, scotopic vs. photopic, but the following still works :D..) I've tested this in practise with a tv-remote controller. When your eyes have not accommodated to darkness, you won't see the blinking of the ir-diode, but in darkness there is a distinct glow from the diode when a button is pressed. I suppose it helps to have a remote with the led exposed. You can try this for yourself if you do not believe.

But, this might work so that you'd make such goggles that block all stray light from the sides of the glasses, kind of like with swimming goggles or -mask. Then use the filters and use these outside during the day. After some time you should be seeing in NIR, for example green plants will reflect NIR light. Try googling ir photography to see the effect, it is quite striking. I have done some IR photography and it is very interesting.

Found the link to the "original" article. http://amasci.com/amateur/irgoggl.html
 
Gotta love Kipkay's salesman voice. The eye can see some near-infrared, but you'll probably be standing there quite a while waiting for your eyes to adjust (while looking stupid at the same time).

A better, though more expensive, way to achive that "night vision" is to modify an old digital camera to remove the IR filter. Webcams work just as well. You do need to replace the filter with a piece of glass of roughly the same thickness to maintain the same focus parameters, however.
 
I suppose you should replace the IR blocking filter with an IR-pass/vis-block filter for it to work properly, or the camera will be sensitive to both.
 
Oh I do, but I put the filter on the end of the camera, not inside it. It's so I can use different types of IR filters (deep-IR, near-IR, etc.). Moreover, the only place to find filter glass of the correct thickness (besides a special order) is to grab one from Lifepixel, and they charge like $180 for one. I made mine with microscope slides and "optical glue."
 
Right, as long as it does the job.

I doubt deep-IR would be feasible with the sensor in ordinary camera's though, as i understand it those are practically blind beyond 1.5 uM or so.
 
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