I've been involved with airsoft for about two years being affiliated with a large local group of people in our community who meet regularly and have scheduled games, ops, and events. Airsoft is a great sport and hobby that encourages teamwork, honor, respect, communication, and discipline (as well as how to wisely make purchases). I recently played a game at night and realized how cool it would be if I could utilize some form of night vision. The more I researched it, the more I wanted to see in the dark somehow.

Unfortunately, true night vision in even the lowest quality can cost hundreds of dollars just for the optic alone, excluding hardware necessary to mount the optic to a helmet or airsoft rifle. It's expensive technology. However, there are alternative methods for seeing in the dark. There are several versions of educational night vision viewers and toy spy binoculars available on the market for kids and...um...well, geeks like me. They utilize low-lux cameras, infrared illumination, and a display for a more affordable $50-$80 system that can still see in the dark. This is the system I chose to utilize.

Being inspired by DIY'ers like Kipkay, and reading books like 50 Spy Gadgets for the Evil Genius, I chose to invest the money to build my own infrared night vision viewer. Besides, both of those night vision builds use parts that can only be scavenged, not purchased individually. I wanted to show how to build a unit from stuff you can buy online easily or at the store.

For more information on how to build this type of system, here's some helpful links:

KipKay's Night Vision instructable:
https://www.instructables.com/id/Super-Nightvision-Headset-Hack/

Longwinter's Steampunk Night Vision Periscope build:
https://www.instructables.com/id/Working-Night-vision-Periscope-Steampunked/

Lucidscience (50 Spy Gadgets for the Evil Genius) Night Vision build:
http://www.lucidscience.com/pro-night%20vision%20viewer-1.aspx

Alex1M6's IR Night Vision illuminator:
https://www.instructables.com/id/Infrared-LED-nightvision-box/

So let's get started. Remember, don't get into any trouble with this, and don't expect this to compete with real night vision devices. This is intended to be aproof of concept. Let's begin!

Step 1: What You'll Need

To quickly summarize how our device will work, it is simply a camera that can see infrared light that is invisible to the naked eye, and can utilize the infrared light like a flashlight. Usually a form of display is required. Often times, the use of a viewfinder from an old camcorder is used for this purpose, however these are hard parts to find without buying an entire camera, and I didn't have any cameras lying around, and I certainly wasn't going to waste money on an entire camera that I was only going to use for a viewfinder. So I used an LCD screen for this purpose instead. Here are the parts you'll be needing for this project:

Cost:
I spent about $60-$70 on electronic components for this project (excluding replacing a part that I ruined), and around $25-$30 for the boxes for the enclosure. If you build your own enclosure, you can probably save a lot of money. If you build this exactly like I did, you'll probably expect to spend around $100 give or take.

Electronics (Prices as of 5/16/13):
-3.5" TFT LCD screen....... $20.00
(http://www.amazon.com/3-5-Inch-TFT-Monitor-Automobile/dp/B0045IIZKU/ref=wl_it_dp_o_nS_nC?ie=UTF8&colid=1O1ZIWOSSBYGI&coliid=I3T7G8S5HAVZ7F)

Takes 12V, has two video inputs- yellow and white. The white input will override the yellow making the white input suitable for other external axillary usage for other AV equipment.

-Low lux video camera module...... $31.40
(http://www.amazon.com/SecurityIng-Surveillance-Security-Degrees-Support/dp/B005FE88VE/ref=wl_it_dp_o_nS_nC?ie=UTF8&colid=1O1ZIWOSSBYGI&coliid=I1M69IMZSUVC2I)

Other cameras will work so long as they can connect to the RCA video input on the screen. This camera is .008 lux rated. The lower the lux rating, the better it will see in the dark and the easier it will be able to detect IR light. I wouldn't go any higher than .008 for this, as the camera won't be sensitive enough to pick up the IR light effectively to create an image.

-30 LED Infrared illuminator..... $13.95
(http://www.amazon.com/gp/product/B001P2E4U4/ref=oh_details_o02_s00_i02?ie=UTF8&psc=1)

IR illumination is usually available in 840nm and 940nm wavelengths and the intensity is measured in watts, not lumens. 840nm IR light will also produce a visible red glow when viewed with the naked eye, however 940nm IR is completely invisible and undetectable. I chose a near infrared illuminator because it was easier to find, and it was more affordable than other IR illuminators.

I also picked up a Cree Ultrafire WF-501b Infrared Torch (850nm, so there is a red glow)..... $19.96
http://(http://www.amazon.com/gp/product/B008RL0KS6/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1)

I ended up getting one of these for my rifle to use in addition to the infrared illuminator for longer distance viewing. Remember, more IR = more viewing distance.

-12V Battery

I was able to get an 8 AA battery holder that adds up to 12V for a few bucks at Radioshack. So long as you use 12V DC, you'll be fine.

-5V voltage regulator.....$1.99 from Radioshack

This is very important because the camera will only accept 5V DC power. Any more voltage than that will fry it and cost you another $30 camera. Trust me, it's not a good feeling to realize that you accidentally ruined your camera and have to buy another one. That's why this instructable is here for you, so you can learn from my mistakes and save money...and probably some profanity as well. :)

-Male to male RCA video adapter:

You'll need this because both the screen and the camera have female plugs for video and need to be connected. You can find one of these at Radioshack for around $5.

-Switches: You'll need a switch for turning on the camera and screen and for turning on the infrared illuminator. Switches are cheap and usually only a buck or two a pop.

Tools/Hardware:

-Multimeter
-Screwdriver
-Soldering iron
-Solder
-Wire strippers/cutters
-Wire
-Heat shrink tubing
-Lighter or heat gun
-Electrical tape
-JB weld
-Hot glue/Hot glue gun
-Drill and bits or access to a drill press
-Dremel tool and cutting attachment
-Black spray paint

Enclosure: This step is completely up to you. I used several ABS project boxes in various sizes from my local Radioshack electronics store and mounted them together to create my enclosure. The sizes I used were 5x2.5x2", 6x3x2", and 8x4x2". You could probably use PVC pipe, wood, plastic containers, etc and it would work just fine.

Completely optional, I also used some cheap 3M full-seal chemical protection safety goggles (lab goggles) to make the faceplate of the viewer and to help prevent light from the LCD screen from leaking and giving my position away (as if the glowing red IR LED's weren't enough). Plus....it does improve the look of the finished unit a bit. :)

Step 2: Wiring

Here's how the system works:

The screen and the IR illuminator will both accept 12V from my batteries. This means that I can power my IR illuminator in parallel to my screen with an additional switch for turning the IR LED's on and off. The camera however, will only run from 5V, and must use a voltage regulator to make the voltage safe to use on the camera. The 12V from the batteries splits off and goes to the regulator as input. The output goes to the camera and connects from the camera to ground as well as the middle prong of the voltage regulator. Because half of our circuit runs from 5V and the other half from 12V, I used the double throw switch to complete the circuit for both halves while still isolating each half. The camera connects to the video input using the male to male RCA adapter. Since we don't need any audio, only the video line needs to be connected to anything.

Step 3: Building the Enclosure

To start, you're going to want to drill holes in your enclosure for your switches, your camera housing, your IR illuminator.

Once all the holes were cut, I mounted all the components into my enclosure and tested it out to make sure it worked before cementing any of the components in place.

After additionally checking my camera to make sure I was right side up, I cemented it in place using JB weld to the inside of the box. I made sure not to get any of it on the circuitry for fear that it would short out something on the exposed circuit board and cost me a (third) camera. I have no idea what that stuff is made of.

The IR Illuminator was simply hot glued in place, as I might want to remove it someday and replace it with 940nm no glow IR LED's.

As for the screen, I stuffed it in the center box after everything else, and centered it where I wanted it to show through the larger box in front of it. After I was happy with the alignment, I peeled off plastic screen protector and cemented the screen to the face of the larger box around the square hole. I wanted to be sure it would fit correctly, so I screwed the box down while the epoxy cured for a guaranteed fit.

Finally, I cut out the lenses of the goggles and cemented the outer portion to the lid of the larger box with a similar shape cut out, and spray painted the goggles and lid black. I used a flat black paint for this to match the rest of my enclosure.

Once everything was dry, I put my batteries in the front box with the camera and illuminator. After screwing the front box to the second, I stuffed all the wiring in it, and screwed the screen and large box on. Finally, I attached the goggles and faceplate and the viewer was complete!

Step 4: Testing

Here's some pics of some indoor shots with the viewer. The IR LED's are almost necessary to see anything in the dark without the IR flashlight. The flashlight really helps a lot with seeing objects farther away. Works great inside!

Step 5: Improving the Sensitivity

One way to really improve the sensitivity and range of your digital night vision is to check for an infrared filter in front of the camera's sensor chip. Usually a pinkish/orange tinted piece of glass, the IR filter reduces how much IR light the camera sees which improves the quality of daytime color imaging, but greatly limits the camera's ability to see in the dark. I was able to remove the IR filter in front of my CMOS sensor using a very small pair of needle nose pliers. I used a Q-tip afterwards to remove the dust that got on the sensor. After screwing the lens back in and focusing it, I was amazed with how well it could see.

Note: Some cameras have the IR filter in the lens. Although you can't remove it, you can replace the lens with one that doesn't have an IR filter on it.

Step 6: Conclusion

After removing the IR filter, this thing can see pretty well. Before, it had a range of maybe ten feet with tons of IR light. Now, it can probably see 50-100 feet out (maybe more?). Definitely a cool build. It does waste a bit of power using the voltage regulator for the camera and the screen/IR emitter, but I haven't had to change the batteries yet on it since I built it.

I couple of issues though, one being that it's a bit disorienting to use. I'm considering changing the design to work with one eye and mount to an airsoft helmet and use an eyepiece lens (just a magnifier) to magnify and focus the screen to match the field of view in the other eye (just like real 1x night vision monoculars). Another issue is this is entirely dependent on IR light to see. Any other device that can see IR light can see you. To the naked eye however, it's still considerably stealthy despite the numerous glowing red LED's on the front. :)