The use of RAW conversion settings can be used to achieve the look of black and white infrared.
By Debbie Grossman [via Popphoto.com]
Open your RAW file in ACR, then head straight to the the HSL/Grayscale tab. Check the box for Convert to Grayscale, then click on the word Default to zero out all the sliders. Drag both the Yellows and Greens up to 100; you’ll start to see the grass and trees begin to brighten in characteristic infrared fashion.
Black-and-white infrared capture turns skies dark, so dial down the Blues slider to –100. Try the same thing with the Aquas slider. Decreasing the Aquas sometimes augments the effect, but sometimes it makes no difference at all.
Now head back to the Basic Panel. Bolster your dark skies and brighten foliage by adjusting the white balance to be bluer and greener. Slide the Temperature to the left toward blue. You should see the sky darken even more. Then move Tint to the left to make the white balance greener, as well.
Adjusting Shadows and Blacks can help you further brighten the grass and trees while darkening the sky. Start by sliding the Shadows to the right to bring them up; you can often go as far as 100. Crank the Blacks up to 100 as well, then dial them back if the effect is too much.
Infrared images often have a blurry, foggy quality. Add it by dialing down Clarity. Don’t go too far—you risk losing all detail when you dial it back to zero. If your image is getting too flat, move the contrast slider to the right to add a bit of definition back.
Infrared film tends to be a bit grainy. To add some grain, go to the Effects tab. Zoom in to view your image at 100%, then adjust the Amount, Size, and Roughness sliders until you get a look you like.