photohio: Fun with IR

On a recent trip to California, I tried out some digital infrared (IR) photography for the first time. All it involves is a IR filter, like a Hoya 72, a tripod and some patience. If you're using an unmodified digital camera, like I did, you just have to use fairly long exposures (30 sec - 1 min) since the manufacturers place a "hot filter" to specifically block IR. These long exposures are also why a tripod is pretty much a necessity.

After taking the photo, you pretty much have two options (1) convert to black and white or (2) do some additional tweaking for a color IR image.

If you convert to black and white you don't have to worry about fixing the color balance due to the red IR filter. As you might expect with a deep red filter, the images are very contrasty and greens (like trees and grass) will be white and blue skies will be darker.

Going the color route, it's handy if you have a sample shot with a white card of some sort, then you can just use the auto white balance in tools such as iPhoto or Aperture. If that's all you do, you'll be left with something similar to the first image below. Again, the greens are white (though mine have a bit of a blue overcast) and the blue skies are darkened. If you want something a bit more dramatic you can go one step further and switch the red and blue channels using something such as Photoshop (as in the second photo).

All in all, I was pretty happy with the experiment, and can't wait to do some more IR photos this summer, especially of Woodland Cemetery and Arboretum.