This project is one of my all-time favorites.
Although it’s something that would be considered ‘high-tech’ by most people, night vision is
actually a fairly simple thing. There are two types of night vision technologies; amplification
of ambiant light, and emission and detection of non-visible spectrum light. This device is the latter.
It opperates by emitting infrared light, which is invisible to humans, and then detecting the light using
a small serveilance camera. It turns out that cheap CMOS camera modules are quite sensitive to IR light.
The image is then displayed to the user through an old fasioned CRT (cathode ray tube) viewfinder.
A viewfinder with a real TV picture tube (nowadays they’re all digital) was the first thing I
needed to get, but it took me months of combing thrift shops before I found one. Eventually I
did, though, and after buying an el-cheapo video surveillance camera, I set to work.
The wires coming from the viewfinder were easily identified as power, ground, signal, etc. I
put everything into a plastic box I had lying around, along with a battery, and powered it all up.
Unfortunately because the video camera outputs a composite video signal, I don’t have any
pictures or video of its night-vision capabilities to show you here. However, it does work well;
look through the viewfinder in the dark, and you get a pretty clear, black-and-white image of the
scene in front of you. I even added twenty infrared LEDs which increased the camera’s view out to
about thirty feet.