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This is a very simple project and it doesn't require a circuit board to be made. We are going to convert a cheap web camera to an infrared camera, capable of viewing in the dark. You can use the IR camera for to a home security system (surveillance system).
The only thing you need is a infrared light source witch is invisible to the naked eye. But this is the subject of another project!
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As you may know web cameras include CCD sensors (charge-coupled device) witch are sensitive to the near infrared (and of course to the visible light). In order to block infrared light, the manufactures including a filter between the lens and the CCD sensor, to allow only the visible light to pass. However still a small amount of infrared light manages to pass. That is why you can see the light coming out form an infrared LED with your webcam.
- One cheap webcam (I bought mine for 12 Euros). You can use a more expensive webcam for better results, but make sure you don't want it any more.
- Some kind of infrared light source (e.g. a lamp or a number of infrared LED's). The more light the better.
- Some film negatives (prefer the ones for color pictures).
Attention: It's possible to destroy your webcam by following this procedure. Make sure you don't want it any more!
As you may know web cameras include CCD sensors that are capable of capturing both visible and infrared light. Manufactures include a filter to block the infrared light, but some of it still passes through. This is the main reason you can see the light coming out from an infrared LED (look at the next picture). These type of LED's are emitting infrared light invisible to the naked eye.
If we remove the filter then more infrared light will be captured from the webcam. We can use this phenomenon in surveillance systems (for example watching a dark room). Even if we light the room with infrared radiation it will remain dark to our naked eyes (and to the intruder!).
Conversion steps
I will describe the procedure with few simple steps. First we will need a standard usb webcam. I selected a joker webcam by crypto. The are two main reason for that. It's a cheap webcam (so if we accidentally destroy it, we won't loose a lot of money) and it's easy to hack.
Disassembly the camera. Unscrew the focusing lens until it's completely removed
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Remove the infrared filter from the back of the lens. It was impossible for me to remove it without breaking it. Be careful when breaking the filter to avoid destroying the lens
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In order our webcam to work as an infrared camera, we must replace the original filter with another one. The trick here is to block normal light and let infrared pass through. The best (simple and cheap) choice is to use film negatives (from the old times of analog photography) like the one in the picture
Cut the dark area of the film in small squares and place them where the original IR filter was. They must have approximately the same size as the original filter.
Attention: Don't use the area where the actual negative of the picture is. You will not have the desired results.
For better results use more than one (I used two, but it's possible to have better results by using three). Make sure you cut the squares big enough in order to stack inside the area of the original filter.
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Attention: Avoid touching the film with your hands and make
sure it's clean. Make sure the lens is also clean, before fitting
the squared film filters. Don't use super glue to fit the filters in
place. It may accidentally go to the lens.
Note: This was one of the
reasons I selected the crypto joker camera. It has a nice area for
fitting the negatives without the need of a glue.
In the following picture you see how things look in infrared (the light source is a lamp which is also emitting to infrared)
Note: Notice how bright an infrared LED is (the original filter was blocking most of the infrared light).
The same picture in a dark room. Our light source is just a TV remote control
Seeing in the dark
In order to see in the dark we need an infrared light source. A lamp is our first choice but it emits visible light too (an the intruder will see it). So the next solution is using infrared LED's
Note: Crypto joker webcam has build in LED's, for viewing in the dark. These are ultra bright white LED's (see the picture below) and they are not emitting in infrared. The first thought was replace the existing LED's with infrared ones. Unfortunately there is one problem. The driving circuit is not designed for infrared LED's, which means they will not emit a lot of light (infrared). In my experiments I had more light coming out from a TV remote control (which has only one LED) even when I replaced all six of the original LED's with infrared ones. Short-circuiting the internal current limiting resistors didn't help much.
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My goal here is capturing images from a completely dark room. So I will need more than six LED's to accomplish that. So why not doing something extreme like the *(not uploaded yet)*
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