Basic Technique for Developing a Color Cast in Infrared Images
In Part I of my Intro to Digital Infrared Photography, I described how to take Digital Infrared photograph and develop it into a monochrome image using Photoshop Elements. Monochrome is an excellent format, but color can add additional interest and depth to a shot.
Below I will describe how to manipulate a Digital Infrared Shot with Photoshop to develop an image that has a color cast, such as the one below.
Color isn't really a meaningful concept in the IR band, but color is hidden in the picture if you know how to find it.
First thing to keep in mind is that you must use the camera's RAW format, recording in JPEG just won't work if you want to develop a good color cast in your infrared photos. You'll want to use as much image information during processing as possible, and this is accomplished with RAW format.
After you have taken your IR shot, open the RAW file with Photoshop, I use Photoshop CS2 and the following description uses Photoshop CS2.
Here is the image in RAW as taken.
First, you must change the white balance to Custom and change the temperature setting to 2000 and lower the Tint.
Now save the image as a JPEG and open the JPEG. Using the Layers menu, duplicate the image, then using the Layers menu again, create a New Adjustment Layer - Channel Mixer. Now you will adjust the Red Output Channel so Red = 0 and Blue = 100, as shown below.
Then adjust the Blue Output Channel so Red = 100 and Blue = 0, as shown below.
Now from the Layers menu Merge Down the Channel Mixer layer.
Again from the Layers menu, open a New Adjustment Layer - Levels. Adjust the RGB and Red, Green, and Blue. To create a pleasing color and bring out some of the blues in the sky. Sorry, I can't tell you exactly how to do this, each photo requires different adjustments.
From the Layers menu, Merge Down the Levels Adjustment Layer.
Lastly, in this photo I want to make the sky a little bluer. Using the Magic Wand Tool I highlight the sky. Then from the Image menu select levels and add a littl blue to the sky. Finally I reduce the image size and from the Filter menu I sharpen the image.
Here is the final image after adjustment.
Infrared red requires digital modification to bring out a 'good' picture. When using the Pentax K100D, the unprocessed IR shot taken directly from the camera is very red. Below is the shot when it comes straight out of the camera. The red tone can be varied by adjusting the white balance before taking the shot. But since infrared is in the red portion of the light spectrum, the original shot looks red.
Below are a couple of other digital infrared images I prepared using the process I described above.
Digital photography is a lot of fun, but exploring infrared with a digital camera adds a whole new dimension. For a few bucks, the cost of a Hoya R72 filter, on top of your digital camera, you can really have some fun. It's just too bad that Photoshop CS2 costs so much.