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  #1  
Old 09-24-2008, 10:55 PM
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Default Show idea: DIY Night Vision Goggles

I think this show idea is right up Systm Street (and then down Revision3 avenue, in the dark), DIY night vision goggles.


Main ingredients:

Cheap LCD glasses
Small black/white CCD camera
Bunch of infra-red LEDs
Battery pack for camera+LEDs


LCD glasses: a couple of good ones to look out for 2nd hand for this task are Olympus FMD-200 & Sony Glasstron PLM-A35, sure they're old & have low resolution (not even 320x240) but the optics of both are good so you get a big field of view and you don't have to get your eyes dead square in the center - some of the newer LCD glasses I've owned (iTheater 320x240 res, & Rimax Virtual Vision 4.0XL 640x480 res) have crap optics & narrow FOV LCD screens inside so even if you try and adjust their position you still get dark opposing corners.
The Glasstron PLM-A35 have easily available batteries and only use 1.5watts so the standard capacity battery will last a few hours. The Glasstron PLM-S700's whilst having an amazing picture res/quality use 13watts so your battery runs down quick.

Camera: For this purpose a black/white CCD camera is ideal because they see IR light and usually have a very low LUX rating. You can use a colour CCD camera but you need to remove the IR filter from the CCD chip or lens before it'll see IR light but won't be so sensitive in low light. Avoid CMOS cameras for this idea, the cheap & easily available ones are crap in low light levels.

IR LEDs: there are two main wavelength types, 850nm & 940nm. The 940nm type are completely invisible to the naked eye whilst you can see a faint red glow from the 850nm type. I believe the 850nm type are brighter when viewed with an IR sensitive camera.

Battery pack: Most CCD cameras are rated for 12v input but can run fine on 8x 1.2v rechargables, or 4x 1.2v rechargables with a DC-DC boost converter (such as the AnyVolt Micro). Calculating resistor values for whatever LEDs you buy & what battery pack you decide to use is very easy with the help of this page http://led.linear1.org/led.wiz

Now all you need to do is work out how to mount the camera & LEDs to the front of the LCD glasses & wire it all up.


As for how bright an image you get from the setup depends on various factors; low LUX capability of the camera, wether the LCD glasses have brightness/contrast control (Olympus FMD-200 have b & c, Sony PLM-A35 have b), and how many LEDs you end up using.
A few weeks ago someone made a video on how not to hide your face from CCTV cameras with IR LEDs, so I did a video response using 3 different cameras & 12 high intensity 840nm IR LEDs, this will give you an idea of how much can see under IR light: http://www.youtube.com/watch?v=2y3HWR3NMDQ

If you're wondering, when I had the Olympus glasses I did do a rudimentary test with a camera and some IR LEDs but didn't take it further or permanently attach it to the glasses. The effect worked quite well, a little weird walking around your house & up/down stairs because there's no depth perception (single camera) and would never drive or ride a bike with them. Outside I couldn't see much because I was using a CMOS camera and only a few IR LEDs, but now I've got a better camera & a bag of decent IR LEDs I may have a go a re-doing it one weekend with my Sony glasses.


edit: these are a couple of commercial night vision LCD glasses:
http://www.allthingsdigi.com/night-v...ape-p-158.html - this is what I had in mind when I was thinking of making my own, but cheaper.
http://blog.wired.com/geekdad/2008/0...vision-go.html - $80! but you only get vision in one eye, and they look, well, urgh. And for that price I bet they used a CMOS camera.
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Last edited by haku : 09-25-2008 at 04:34 AM.
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Old 09-25-2008, 09:23 AM
mad_jihad
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That actually looks doable the only thing that would be a little hard is getting the camera to output to the glasses, also the camera would need to be decent not some 5fps web cam or you would trip and break the NVGs u just made lol.
I for one would like to see this on Systm, there is not that many things more bad ass then DIY night vision goggles.

Edit: I think u could get rid of the depth perception problem using mirrors (the mirror in front of the camera is like a V with the camera being under the V and two more mirrors like / to bounce the light in the right direction.) to split the single camera view in half and display each half for different eyes.

Last edited by MAD_JIHAD : 09-25-2008 at 09:31 AM.
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Old 09-25-2008, 11:29 AM
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Connecting the camera to the glasses is as easy as plugging two connectors together, almost all the consumer level LCD glasses you can buy accept composite video input, which you'd plug a camera into that outputs composite video, so no problems about the framerate because you'd get 59.94fps (interlaced NTSC) or 50fps (interlaced PAL).

This is exactly the kind of camera you'd use for this project, small, cheap, good low LUX capabilities and easily focusable.

The depth perception problem is because both eyes are seeing exactly the same image, if you can get glasses that can take two video inputs then two cameras would give you depth perception.
I do have some LCD glasses that can take two VGA or composite signals, one for each eye, but the controller box is heavy and about the size of two VHS tapes and needs 5v at 3A! you'd need to carry the battery+controller box in a backpack.
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Last edited by haku : 09-25-2008 at 11:31 AM.
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Old 09-27-2008, 09:53 AM
mad_jihad
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duh why didn't i think they'd have composite in, well that makes it allot less complicated.

That mount that the mini b&w camera has would make for easy tilt adjustment which would be good or it could be pointing to high/low.

Probably another thing that might be a requirement is auto focus.

So far i think you would need:
Black and white 30+fps mini camera with composite output (auto focus?)
LCD Glasses with composite in
6-10 Infra red LEDs(not sure if that would be enough)
also im not sure on what size battery pack you would need.

Im pretty sure that the low light goggles military's use usually have 1 camera on them and that there are depth perception problems with those as well.
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Old 09-27-2008, 03:34 PM
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I've not seen any autofocus mechanism or camera of the size needed for this project, but it's nothing to worry about really because with these small cameras if you focus so you can see something clearly 6 feet away you'll still be able to see things ok 20 feet away, it's only when you get close up (2 feet and less) you may need to adjust the focus.
Then again you'll probably only be using LCD glasses with a resolution of 266x225 or 320x240 so you can't see a lot of detail with them anyway. 640x480 resolution glasses blow away the lower resolution glasses in terms of detail and 800x600 enables you to get full resolution from the camera - but the price of them sharply increases.


LEDs, you could have a switch for different numbers of LEDs so if you want to see something in the distance you switch all of them on and for closer you only have 1/3 or 1/4 of them switched on.


I've just tried powering a typical CCD camera and 12 high intensity IR LEDs from an 8x rechargable AA pack, the camera+LEDs are using 1.65watts (camera 1.05w, LEDs 0.6w), so with a set of fresh charged 2000mAh AAs you could theoretically expect up to 11 hours runtime.


'True' night vision devices have two main flavours, monocular & binocular (essentially two monoculars), with different generation levels reflecting on how good they are at seeing in the dark. http://en.wikipedia.org/wiki/Night_vision_device has information on the different generations and a diagram of how they work.
I have a generation 1 night vision monocular which works pretty well and has a single IR LED that can be focused into a small spot, but your arm easily gets tired holding it up to your face and pressing the the main button, hence my interest in this kind of project.
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Old 09-28-2008, 07:37 AM
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Yea your right you wouldn't need auto focus, on any good SLR camera they have an infinity focus which is probably what focusing it all the way out does on the ccd camera so there shouldn't be any problems with the diy low light goggles focusing.
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Old 09-28-2008, 07:19 PM
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I am in the process of attaching the B/W camera I used as the 3rd camera in the above YouTube video clip, along with 12 high intensity IR LEDs to my Sony LCD glasses, camera+LEDs+glasses all powered from an 8x rechargable AA battery pack.

One thing I was hoping wouldn't be so much of a problem was the camera, it works perfectly but the weight of the metal housing means it really presses the LCD glasses down on your nose - so ideally the best camera you want is a CCD board camera (no housing at all) with 1/3" pickup that is 0.1LUX or lower rating. I've got my eye on what looks to be a perfect B/W CCD board camera which I may get in a week or so.
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Old 09-29-2008, 02:09 AM
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Finished!

It's dark here (3am) so did a test by going from inside to outside and along an unlit lane.

Very weird & cool experience.

It's just a first revision of the setup so there are a few things needed to fix for the second revision;
1. narrower angle lens so you get as close to 1:1 magnification as possible because the one I have is too wide so when you walk up/down a couple of steps you're likely to trip over them because they appear to be further away than they actually are.
2. lighter camera, the weight of the metal casing makes it awkward to wear as they keep trying to slip off your nose
3. switch for 12 or 24 LEDs, first 12 wide angle (basically you cut the heads off to make them wide angle) and the second 12 left alone but for seeing further in the distance
4. reduce number & size of cables, there are 3 extra cables running along side the LCD glasses cable; camera power, LED power, video from the camera - all this can be condensed into just a single (thin) 3 core wire; ground, +v, video
5. maybe figure out how to tap power from the battery pack on the LCD glasses control box, so when you turn the glasses on it also powers the LEDs+camera

I'm too tired to take some pics & video footage at the moment, hopefully I'll have the time+energy tomorrow night.
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Last edited by haku : 09-29-2008 at 02:13 AM.
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  #9  
Old 09-30-2008, 02:41 AM
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Ta-da!





The first 3 pictures the IR filter is on the camera, the rest are without the IR filter.

The last 3 pictures are of the actual LCD glasses display, bit difficult to get the camera dead center to take the picture but you get the idea, and the actual image you see looks better in real life.

I'm definitely going to do a 2nd revision of this setup, things need sorting out...
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Old 09-30-2008, 06:07 AM
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Interesting hack. Real night vision glasses don't have the LED illuminators, as they would be detected by the Bad Guy's night vision goggles. That would make you a target.

So the real ones just collect ambient heat. And they magnify the heck out of it.

Still cool hack
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