The Challenge of Infrared Photography

San Juan Mts AU11-486-IR2

Just as there are certain wavelengths of sound that cannot be heard, so there are wavelengths of light that cannot be seen. What is known as infrared refers to some of those wavelengths. The eye can’t see them, but the camera can. Or at least it can under the right conditions. Most digital cameras filter out the infrared portion of the light spectrum. But the filters aren’t perfect. If you block all the other types of light and only let infrared light through, you can create infrared image, assuming long enough exposure time. To block out all non-infrared light, you will need a filter such as the Hoya R72 filter:

This filter is so dark, once you put it on the lens, you won’t be able to see through the camera’s viewfinder. To gain proper exposure may require shutter speeds approaching 30 seconds. The resulting image will look something like this:

If you open them into Photoshop and select Image > Adjustments > Channel Mixer you can start playing with the colors. You can use levels, color balance, and other color controls to try to fine tune your image. Or you can switch to black-and-white (the Channel Mixer box comes with presets for black-and-white IR). It’s tricky and I can’t say I’ve entirely figured out any special recipes for getting consistently good results. It’s still fun to play with. With the right tweakings this:

can be transformed into something like this:

Other examples: