Well, let's get started. To begin with, you don't need a web camera itself.
I bought the simplest one with a resolution of about 640x480, it doesn’t matter, any other will do.
We need to remove the infrared filter (IR filter) from it so that our camera can see infrared light.
These filters are found in almost all cameras.
We take the camera, there will be a small recess at the top - we pry it with something sharp and remove the top peel. This will also give us access to the other latches that hold the two halves of the camera.
There is a small rubber plug on the side of the camera - you need to pick it out with a sharp object (dentists know what I'm talking about :-))
There, in the depths, the narrow-eyed Chinese hid a small screw - we unscrew it with a Phillips-head screwdriver.He turns away with difficulty, largely because someone was not too lazy to make a whole shaft and hide this tiny screw there.
Once you unscrew this screw, the chamber can be opened for further experiments.
Now, carefully and without applying excessive physical force, insert something sharp into the groove and open the two halves of the chamber. The groove will be at the top of the chamber:
Let me remind you that after all our experiments, the camera will remain alive and will continue to work successfully. Having opened it, you can turn it on and see - everything should work fine.
Yes, there are a few wires inside, one stunted LED and a cheap matrix. In the picture, the camera is half disassembled and turned on, working perfectly.
We carefully move the black head with the camera optics towards us - it must be carefully removed along with the board from the groove in which it rotates. You don’t need to remove them completely, but only from the grooves.
That's it, now unscrew the head with the optics until it falls off the board. After that, looking into the camera, you should see the matrix.
It is very advisable not to touch it with anything and generally put the camera aside so that nothing gets on the matrix.
There is a subtle point here. The fact is that the IR filter is inserted inside the head with optics and a thin edging is fused on top, which needs to be removed. This must be done decisively, not forgetting that the IR filter is glass and can be easily broken. The picture shows three arrows pointing to sections of plastic piping that need to be carefully cut
After this, you will immediately hear the glass creaking - this means that you are scratching the tip of the IR filter.We are almost there, now we need to reduce our efforts and carefully pry the IR filter out of its plastic embrace.
After we removed the IR filter, we put everything back together. We turn on the camera and look - everything should work, but the image will have slightly strange colors. This is fine. Here's nature in infrared:
In general, camera sensitivity sharp will rise and the bright light will blind her, but in the dark she will be even more sensitive than the eye!
All is ready !
Now we direct it to the banknote.
This is what it looks like on the screen.
100 rubles
1000 rubles (less contrast than 100 rubles, but everything is clear)
General:
(click to enlarge)
Important Note: The operation of the camera is greatly influenced by lighting - if there are only "daylight" light tubes, then the picture will not be very contrasting (see photo) - cold light, a lot of blue, little infrared. Much better image when illuminated with conventional incandescent lamps. (The ideal picture is obtained by lighting the money with the flame of a lighter! :)
Now we will make a so-called night vision device from our camera.
The most important thing is that after removing the IR filter, the sensitivity of your webcam should increase significantly, which is very useful when shooting in low light conditions. More light means higher “signal noise” of the image, that is, better image quality. So a good black and white image is better than a very noisy color one.
Great sensitivity and the ability to see in the dark are very useful if you need to make a small security camera.
We need to make IR illumination for the camera so that it can see in complete darkness. I took a couple of IR diodes, namely, I unsoldered them from an old remote control for a video recorder.I connected them in series plus through a 100 Ohm resistor. and powered them from the same chamber. 5 volts are supplied to usb.
This is what happened. Scary, because it doesn't have a case.
with diodes on:
In the photo, the camera films itself and therefore the light of the IR diodes is clearly visible, the light of these diodes is not visible to the ordinary human eye!
Sees in complete darkness at a distance of 3 meters. Of course, 2 diodes are not enough, you need at least 6, but I didn’t have any more.
When using about 10 - 15 diodes, the camera will be able to see 15 meters.
My keyboard is in complete darkness.
In general, in infrared light, some objects become unusual: a T-shirt with stripes becomes white, some things are transparent, for example, like Coca-Cola in the picture:
It is transparent, like water. This is because infrared light passes through some objects while visible light does not. Well, we have already talked about paper money in infrared light. . .
In short, if you have imagination and ingenuity, you can do a lot of things from a webcam. And in general, it’s useful to keep this in mind - you never know what kind of engineering problems will have to be solved...
