See In The Dark, The Simple Way

Night vision googles used to be the exclusive preserve of the military, and then of the well-heeled. Image intensifier tubes were very expensive, and needed high-voltage power supplies to keep them going. Now that we have solid-state infra-red cameras the task of seeing in the dark had become much simpler, and [Alex Zidros] is here to show us just how easy that can be. His night vision goggles take a selection of off-the-shelf parts and a little bit of 3D printing to produce a complete set-up for a fraction of the cost of those night-vision goggles of old.

At its heart is a little NTSC/PAL LCD display in a 3D printed bracket. These used to be a small display of choice, but we see them rarely now because standalone displays and the microcontrollers to drive them have become so much more useful. Driving the display is a video camera with its IR filter removed, and providing illumination is an IR flashlight. In effect it’s a classic analogue CCTV system in miniature, but the most important thing is that it works.

We might have expected a Raspberry Pi Zero and NoIR camera, but it’s difficult to argue with a functioning night vision system. If you want to look at a project with an image intensifier tube though, we’ve covered one of those in the past.

42 thoughts on “See In The Dark, The Simple Way

    1. Im waiting for passthrough vision on Valve Index headset to be hacked with FLIR cameras for real time augmented heat vision

      I want my stereoscopic real FPS predator vision now, damnit

      1. Somewhere recently I saw the idea floated of using thermochromic liquid crystal stuff (Which I think you can now get similar in a coating) as used in forehead and aquarium thermometers, with huge fresnel lenses (Checked for IR performance) with a camera on them to see if one can create a thermal imager that way. But I think those tend to react pretty slow. Possibly the problem is the thermal mass of the substrates on which they are used. Get some on a 1 micron mylar film in a halfassed vacuum and we might be in biz.

        1. That may have been me. I have a 15-cm square sheet of the stuff, with a “full page magnifier” Fresnel lens focused on it.
          1. Yes, it’s slow. It’s also not very sensitive.
          2. The IR fresnel lens must be polyethylene. Most of the dollar store ones seem to be plexiglass/acrylic now, which absolutely does not work.
          3. The liquid crystal sheet must be parallel to the fresnel lens: the depth of field is essentially zero, so it can’t be at any significant angle.
          4. …Which means the optical camera viewing must view the thermochromic film way off axis. Not a huge deal: use a small sensor so it has a big depth of field. DSLR won’t work.
          5. You’d think you could illuminate the IR on the backside of the film, and look at the thermochromic image from the other side, but that’s even slower response and poorer sensitivity.
          6. You must carefully maintain the temperature of the box holding the film to bias the film into its sensitive region: too cold or too hot and you get no response. Non uniform or drafty, you get spurious “signal”.
          7. You need to figure out how to map the film colour (actually, hue) to temperature.
          8. You need to figure out how to light the film evenly to get its optical picture, not get specular reflections, and not get the room light itself form an image on the film. I think you might be able to use black polyethylene to block room light and pass IR, but I never got that far: the simple expedient of just working in the dark was enough to prove the concept, after which I lost interest.

    2. I don’t have a homemade pass-through thermal/night vision scope on my .22LR for hunting raccoons. It’s not using an MLX90640 sensor and a NoIR camera. Definitely not overlaying thermal over regular video and outputting it to a HyperPixel 4” display set up in a 3d printed case with a lens from a cardboard VR setup.

  1. I’ve got this kind of a lashup with one of the phone VR headsets with 2 smaller old android phones in, with their cameras having a clear view forward. I haven’t got round to pulling the IR filters yet though. It’s intended to mount IR LEDs for illumination. Also I want a belt pack with a pi or android box, and a big battery, that will communicate with the phones over wifi and/or USB (Better data rate than wifi, and you keep the batteries topped) to image process and provide some AR help. At the moment it’s all kind of a work in progress messing around rig, with nebulous ideas and intents.

  2. Nice. Aren’t the military type night-vision goggles quite different though, in that they actually amplify the low levels of light (hence the expense)? That way, they don’t need to use IR illumination, so you can see but not be easily seen yourself.

    1. That’s what I recall from the time about fifty years ago that Popular Science or Popular Mechanics had a cover story on night vision scopes. They were big in Vietnam at tye time.

    2. The current version (Gen 5 I believe) are so good that the image intensifier tubes are better than the eyes of an actual cat. I had an interesting discussion with an Air Force pilot who claimed he “borrowed” a set and used it to annoy the cat in darkness so complete that the cat freaked out.

      Current versions include synthetic color and integrated thermal/intensifier images. They’re also apparently wireless which strikes me as particularly dumb if you’re trying to conceal your position:

      “Anyone out there?”

      “Can’t see anyone, but I just hacked their contacts list and sent their spouse a nasty Email…”

    3. Correct. These would be the equivalent to early night vision attempts (Active Night Sights) that use an IR light source to augment the existing lighting. They’re not bad, unless someone out there has the same set-up or newer. Then, your active illumination source is literally a freakin’ beacon.
      These are pretty good if you’re not worried about broadcasting your position. But you also have an issue with the illuminator being too bright (transitioning from outside to inside presents some issues with flaring). I think those issues could be overcome with some smart hacking, especially as higher generation night vision gets more expensive very quickly as quality goes up.

  3. Lately, my fuji x-t20 with a chinese f1.2 35mm is so sensitive that the view on the lcd gives more visibility than the naked eye. Without IR illumination, just on amplification of ambient light.

  4. And everyone else with any ability to detect IR can now see you like a beacon.

    Image intensifier tubes are not that expensive. You can easily buy NV scopes and monoculars for under $300 if you look around. I’ve owned several and they are leaps and bounds better than any camera/lcd setup in terms of image quality and actual usefulness.

    1. What kind of complete monocular can you get for $300? Last I checked, gen 3 tubes were over 4 figures each, and that was for blemished (black spots in the image) tubes only without the googles or monocular to use them.

      1. Yep I was gonna say for that price you are in gen 1 or perhaps salvaged gen 1 cascade territory. May be able to even get a bare gen 2 blem/”untested” tube for that price. Definitely not anything newer or in better condition.

  5. I recall using a Sony “Nightshot” camcorder sometime around the turn of the millennium that did this too: In nightshot mode it had a switch that physically removed its IR-blocking filter and turned on a IR LED. Worked in pitch black rooms, but the range wasn’t so great — kinda pooped out past 5-6 meters or so.

    Rumour was that it was discontinued because certain fabrics were transparent in the infrared, and somebody’s panties were found to be in a twist.

  6. I remember a story about the U.S. military getting utterly panicked due to an event in the Artic/Alaska ( until they figured out how to enhance UV..)

    I am uncertain if there was a confrontation OR a blind side in thinking.

    So, due to how cold it is in the Arctic, Polar Bears actually have all black skin to absorb the heat, each hair is a piece of fiber optic.

    Hence they are invisible except for nose and eyes on infrared because there is no IR light reflected from them.

      1. Oh, the part about the hair being fiber optics is complete BS, but the low IR signature is not. Good insulation (fat and fur) provides for a low surface temperature, and the unpigmented hair (fur) has relatively low albedo (and therefore low emissivity), and high scatter (i.e. incoherent reflection). Translation: it’s not very warm, not very bright in the IR, and reflects a lot of its surroundings. No wonder it’s hard to see in the IR.

  7. Raspi NoIR sensor is too small for good night vision. You would be better off with a very sensitive large low resolution sensor coupled to a good lens. Some sensors will work with only starlight…

    1. True, but the V2 sensor does have on-chip (analog) 2×2 binning, which brings the pixel size up to a not-hopeless 2.3 um square. Do another 2×2 binning of the digitized data (*) and the 4.6 um pixels are big enough to be useful.

      (*) Analog binning is preferred, since the pixel readout noise is added *after* summing the pixel signal, so the SNR increases proportional to the number of pixels binned. Binning the digital signal means you’re also summing each pixel’s readout noise but, since that noise is random, its contribution to the total noise goes only as sqrt(bin count), while the binned signal is a simple sum(bin count): The noise in the resulting digitally-binned image is reduced by (sum(bin count) / sqrt(bin count)) = sqrt(bin count).

      Incidentally, the relatively large but cheap and available MT9M001 sensor has 5.2 um pixels, which makes it a credible detector for low light, but unfortunately, its 2×2 and 4×4 “bin” mode is really just a subsampling (skip) mode: it only samples every other (or 4th) pixel, which speeds it up, but it does NOT sum the analog signal from adjacent pixels, sadly.

  8. Probably the epitome of consumerism here; A Sionyx Aurora is COTS non-ITAR controlled option that likely performs a lot better than this. Kudos to the guy for building something from scrap for probably next to nothing, but if you’re thinking about tackling this, and don’t have the parts on hand, buying an Aurora is something you should weigh.

    FWIW I have one, as well as real Gen 3 as well as Gen 4 NVGs. They’re not even close in regards to performance, especially below 50% illum without supplemental IR. But for the price of entry, $350 US for the sport model, they cannot be beat for the $ to smiles ratio. The downsides to them are the quite shit eye relief for the viewfinder, 30FPS in night/twilight mode, not really suitable for use as a clip on NVG for weapon sights, and supplemental IR being needed as mentioned earlier.

    Lots of folks get wrapped around the axle about the need for supplemental IR. Short answer, unless you’re in a scenario where you’re gonna get killed using an IR light source they’re perfectly fine.

  9. I once tried this with a very expen$ive low lux (RIP) camera and an old Myvu goggles set that I’d modified to use green backlights instead of white and two high power triple junction IR LEDs.
    It worked for a while but alas someone didn’t check the voltage and something bad ™ happened to the camera.
    Glasses still partially worked on one side but it was clear that it had damage.

    Incidentally a lot of the cheap sets used fragile ribbon cables so its best NOT to take it apart extensively if possible and simply install a green and red LED in series with a centre tap so one side can be turned on at a time
    This also has the advantage that if needed yellow can be generated which is better for some applications.

    Also some old Sony Hi8 and miniDV camcorders used a monochrome microLCD panel but needs some work.
    Backlighting it and then using sequential RGB is possible but a lot of work though this is simple enough to feed from any old laptop or RPi and there is actually a sequential output option already on the latter.

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