Infrared Camera
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History of Infrared
Read about the history of infrared at Mywiseowl.com
Infrared can be found in everyday life. It is used in security systems at shopping centers and for satellite imaging of storm systems.
Infrared imaging continues to enchance the limitations of human sight in new and innovative ways.
How to Build Your Own Infrared Camera
A cheap way to build a relatively inexpensive "near infrared" camera is to use a Webcam. The CCD (charged-couple device) chip inside the webcam is sensitive to infrared. To avoid exposure to infrared manufacturers only use an infrared filter that will block infrared light and let other wavelengths pass. Therefore to build your near infrared camera all you have to do is to open the webcam, remove the filter, and replace it with a "dark" filter.
Since this procedure involve some risk, i.e. permanent damage to a webcam, use a cheap camera, so you won't regret it if you break one.
Procedure
- Purchase a cheap camera, install and take a picture to make sure it is working properly
- Open the camera very carefully (each camera is different).
- Find the charged-couple device camera, better known as CCD(pictured below), and identify the filter - usually a tiny (about 6mm diameter or square) piece of glass
- Cut a piece of overexposed color film.
- Install the new "filter" and reassemble the camera.
- and there you have it....
For testing, I found it useful to use an infrared LED. If you don't have one handy, you can buy one at Radio Shack, or use the TV remote control.
What can you Explore?
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These pictures show a security feature in 5,10, and 20 dollars bills. A single band is seen on the 10 dollars bill and two distinct bands on the 5 dollar bill. The picture of a fluke voltmeter seen by the infrared camera shows a blank display. Actually most LED displays won't show anything.
What Else Can You Do With Infrared?
Most patterned shirts under infrared will show look blank. It is also interesting to see objects illuminating with an infrared LED.
You can also make an infrared flashlight using the same idea. First, power the LED with a 9V battery making sure that you have a 1 kOhm resistor in series with the LED. This resistor limits the current that flows through the LED.
You can now use the infrared LED and the camera to perform small experiments. For example, verify what kind of liquids or mixtures can be used to block infrared light.
Warning
The modified webcam is not sensitive to deep infrared, or heat.
References
Back to High School Experiments
