True digital infrared

PSA Journal, August, 2005 by Ken Deitcher

Black and white digital infrarred can be simulated with various software programs such as Photoshop[TM], Photoshop Elements[TM], Paint Shop Pro[TM], and many plug-ins.

In traditional photography, infrared was always a problem. The film had to be loaded and unloaded in the dark. The exposures were mostly by guess, and setting the focus could be questionable.

True, first generation infrared B&W imaging can be accomplished only with digital cameras which were manufactured without an infrared cut-off filter over the sensor. Most of the newer cameras have this filter in place. In the rest of this article, I will refer to infrared as IR.

To determine if your camera can "see" IR, place an IR filter over the lens. Point a television remote (IR controlled beam) toward the camera. If you can see the beam of light through your viewfinder or on your LED screen, your camera can record IR.

This is only part of the formula to record true IR. First--can your camera sensor see IR? Second--can you visualize the scene through the viewfinder or LED screen? Third--can your camera record in B&W? Fourth--can your viewfinder visualize the scene through the extremely dark filter?

This ability to "see through" the filter is aided by the electronic viewfinders (EVF) in some digital cameras that increase the optical gain, so that your subject can be seen in very dim lighting conditions. In these cameras, called advanced point-and-shoots, you can also visualize the image before you take it.

The Konica-Minolta D'image 7, a 5.2 MP camera, has all the requisites for IR imaging. The only additions needed are a 49mm IR filter and a cable release. Although this camera is not manufactured anymore, it can be purchased, used, from internet sites such as E-Bay.com and Amazon.com.

I use a tripod most of the time when using this camera, as the exposures at ISO 100-200 and f8 can be as long as 2 seconds. Hand-held images can be taken on very bright days.

The most important point is to set the camera on B&W mode when taking IR images, although interesting effects can be obtained by combining B&W IR images with color.

When taking IR images, you should have a bright day with preferably a blue sky with white cumulus clouds, a foreground point of interest, and green foliage. The foliage will look like fresh fallen snow, while the blue sky will turn quite dark accentuating the clouds. When photographing water, such as lakes and ponds, the water will turn black.

When processing your image in your computer, very little manipulation is required. The first step is to check the levels to increase the highlight brightness and to darken the shadows. These areas can be further tweaked using Photoshop's shadow and highlight filter. Once this is done, use unsharp mask and print.

I usually print the image using my Epson 1280 on Epson heavyweight mat paper. I set the printer to use only black ink, as this prevents any color casts to affect the image. If you desire, you can tone the image in Photoshop by using hue/ saturation or converting to grayscale and using duotone or tritone colors.

Several of the high-end digital cameras can be retrofitted, so they only take B&W IR. e.g.: Canon D30, Canon D60, Nikon100, and the Digital Rebel. The only problem with this conversion is that your camera is now dedicated to B&W IR and the IR image can only be seen on the LED screen after the image has been taken (www.irdigital.net).