False Color Infrared – Digital – Guest Article by Mel Mann
In my previous article, Photography In the Red Zone, I discussed the interesting world of Infrared photography and my experimentation with it. The traditional look of Infrared photography is black and white, and while this can be very dramatic, it’s not the only way you can portray IR photography. There is a version known as false color IR where different colors are matched to specific wavelengths in order to identify objects reflecting them. We’ve seen lots of these images because NASA uses false color IR for many of the earth images made by low orbit satellites. With this you can determine the health of plants, extent of flood waters, differentiate among snow, ice and clouds.
In the hands of a more down-to-Earth photographer false color, IR opens up wholly different color palettes to spice up seemingly mundane images. Selecting specific wavelengths for subjects may not be possible, but since the image generally shows an other-worldly appearance, the choice of colors is entirely in the photographers hands.
Although there is no longer color IR film available, digital IR offers the opportunity to work with this type of photography. All you need is an IR filter for your camera and editing software that gives you the ability to swap RGB channels and modify their levels.
First you need image information, both for IR and color. The following two images were made by putting my camera on a tripod and carefully making the same image twice, once with a Hoya R72 filter on my camera and the other with no IR filter.
Next I opened both images in Photoshop. Starting with the color version, I opened the Channels palette. I’ll show different versions of Channel swapping below but the technique is the same. First select the Channel you want to swap in the color image by clicking on the channel itself to make it the only one active.
Go to the color image and Select All, then Copy.
Click on the IR image to make it active, open the Channels palette, select the same color Channel you copied in the color image and Paste. The Channel from the color image will be put in the image. You can move one or more Channels in this way depending on how you want your image to look.
Once you’ve swapped the Channels you want, open the Levels palette in the IR image. Select each channel separately and slide the black and white arrows to the edges of the histogram. You can put the arrows anywhere, but I usually start with this as a way to see how the basic image will turn out.
When you’ve adjusted all the channels click on the RGB Channel to make them all active. Then you’ll see the final image in false color. From here you can make adjustments to each color using other Photoshop adjustment tools to get the final image just the way you want.
From the two images above here are the results of different combinations of Channel swapping.
With Selections, Masking and other editing tools you can create a worldview that is uniquely your own. My work is landscape so I have a range of colors to play around with; I have no idea what a portrait photographer would do with this technique, but would really like to see some examples!
Not a bad way to explore what’s all around us in a different ‘light.’