Have you ever wanted to see how hot what you’re taking a picture of is? You could use a mere infrared thermometer and measure temperature points like a cave man, or spend thousands of dollars (or a “paltry” $1200) on an infrared camera.
The third option is that you could make a hybrid infrared camera yourself using a camera capable of long-exposure shots (or one modified to do so with CHDK) and a specially modified flashlight. The concept is actually pretty simple. As the temperature of what its point to goes up, the flashlight’s colors change.
Since a long exposure photo (any photo really) records all light coming into the camera, it saves the color you’re projecting on the wall at a certain point. As this modified flashlight’s color varies depending on temperature, the image will come out with colors corresponding to the temperature. If you carefully go back and forth with this device while taking your heat sensitive photo, you should be able to get a pretty good picture of what’s going on heat-wise once the shot is over.
The concept is pretty simple, but construction is not. Fortunately Max decided to post build instructions on this hack, so you can build your own if you like. The build consists of modifying a flashlight using a temperature sensor, several LEDs, an Arduino, and several other parts to get this “temperature projector” working.
If that sounds too hard, I think I’ve found an alternative to flashlight modification in this Black & Decker leak detector (Amazon). As shown above, it displays a green light for temperatures in the range you set, a blue light for cold temperatures, and a red light for hot temperatures. I haven’t tried it myself, but it looks like an interesting device to play with, especially using long-exposure photography.