I have received a number of e-mails (especially through the DDQ) asking how to create an infrared effect on a color image using Photoshop. There are a number of techniques that I have found over the years, and I have reduced them down to a streamlined technique that provides a look similar to infrared film. Of course, I've never shot with infrared film, but I suppose that is one of the beauties of working in the digital darkroom. You don't have to have experienced the real thing to create it digitally.

I have started with this image:

If we simply convert the image to grayscale, we get a black & white image like this:

This isn't the desired result. Green foliage reflects a great deal of infrared radiation, which is just outside the visible spectrum. Infrared film is able to pick up this wavelength, which produces a surreal view that we can't see with our own eyes in nature. To simulate this effect, we need to enhance the appearance of the green layer in particular. So, we start by creating a new adjustment layer for Channel Mixer. Check the box for Monochrome, and increase the Green channel to the maximum value of 200%. We want to try to keep the total as close to 100% as possible, so reduce the Red and Blue channels to add up to about -100%, with the specific balance determined by the appearance of the image. In my example I have set Red to -60% and Blue to -40%. 

This channel mix will sometimes result in highlights in the green channel that are too blown out. If so, you can reduce the output level for the highlight in curves, as shown below. For this image, I didn't need to make this adjustment.

To give the ethereal glow that is seen in infrared shots, we need to blur the image. You will generally only want to blur the green channel, so we will select only the green channel from the channels palette, and then select Filter, Blur, Gaussian Blur. A value of five pixels is a good place to start for a high-resolution image.

Because we don't want the image to be excessively blurred, and we want the green areas to really glow, we'll fade the Gaussian blur but use a blending mode of screen to bring out the highlights. From the Edit menu select Fade Gaussian Blur. Set the Mode to Screen, and set the opacity down between 25% and 50%. The exact amount will depend on your image, so use the preview to determine the best value.

Finally, add some noise to the image to simulate grain. From the Filter menu select Noise, Add Noise. Check the box for Monochromatic, set the distribution to Gaussian, and set an amount that looks good for your image. For high-resolution image an amount of about 5% will probably be adequate, but you'll need to adjust this for your own image.

That's it! You can use this technique to simulate an infrared image, which stands out as very unique compared to the original or the straight black & white conversion.

Original

Black & White

Simulated Infrared