Have you ever noticed those intriguing photographs of flowers or landscapes that look as if they were shot at night, or maybe on the moon? They were probably infrared images. Photographers using film cameras can simply buy and use a roll of infrared film to capture the frequently eerie scenes created using the infrared spectrum. But digital cameras are deliberately designed to block out infrared light. What's a photographer to do?

Fortunately there are a variety of tools that will let you re-create and even go beyond the film experience with digital. Infrared photography is a really fun way to try something different with your camera and also help you learn to see subjects and your environment in a different way.

The simplest way to get a taste of Infrared photography is to use some of your existing images with a software filter that simulates how an infrared image of the same scene would look. Photoshop Elements includes the easy-to-use Infrared Effect as one of the options for its Convert to Black and White command. This handy tool provides a quick and fun way to experiment with pseudo-infrared—of course, a software filter is really only guessing: The filter starts with the knowledge that healthy plants (for example) reflect infrared light very well, so it makes green areas bright. If you want real infrared photographs, you need some specialty hardware.

The infrared light used in typical infrared photography is essentially a fourth primary color. Like the red, green, and blue your camera normally "sees," infrared covers a range of the light spectrum a little bit above red light. Much further past visible red are the other portions of infrared that measure heat, known as thermal imaging, but those require very different sensors, so we'll focus instead on what is commonly called the "near" infrared. —next: Try a Filter >

Try a Filter

The silicon used in digital camera sensors is sensitive to near infrared light, so if we physically filter out visible light, then what's left will be the infrared image. There are a variety of filters available to do this. Some of the best are made by Harrison & Harrison, but commercial filters can cost over $100. One inexpensive alternative is to use unexposed but processed slide film (it looks black). Tape it over your lens opening and it will allow infrared to pass through while blocking visible light. Or you can buy a small "gel" filter that admits infrared for about $30. Look for a Wratten 87 filter made by Lee or Kodak to get started. Any of these filter solutions are a little tricky to use, since they look black to our eyes. That means you need to prefocus your camera before adding the filter. It also requires you to adjust the exposure manually. You may need to add four or even five stops of light to your metering to make up for the loss of visible light. If your camera has a histogram, you'll find it invaluable for this task (for more information, see "Harnessing Histograms"). And of course you can't see through the viewfinder once you've added the filter, so you need to compose first—ideally, using a tripod.

There is one more issue. Since our eyes are not sensitive to infrared (although many animals' eyes are), and because infrared light degrades cameras' rendering of the rest of the spectrum, almost all digital cameras are equipped with a filter to cut out most of the infrared light. So simply adding a visible light filter (often confusingly called an IR filter) leaves us with a very small spectrum of light showing through to the sensor. That results in long exposure times and can increase noise a great deal. Some camera models have very weak IR filters, so this technique works pretty well with them, but newer cameras tend to have very strong IR filters, making the approach very frustrating; even with perfect technique your results with a camera filter will not be as high-resolution, or sharp, as those you can get by doing a true conversion of your camera to infrared. You will certainly want to use a tripod here as well—and also consider a remote shutter. —next: So, Convert It! >

So, Convert It!

Actually converting a camera to capture infrared is by far the best solution, although it's expensive. The conversion is accomplished by replacing the infrared filter in your camera either with a piece of clear glass (to make your camera sensitive to the full spectrum) or with a filter that blocks out visible light (to make your camera a true infrared camera—note that with this option you will not be able to use your camera for shooting regular images). This can be a great use for an older camera that is gathering dust around your house. The infrared filter is exposed during sensor cleaning, and if you've ever seen it you'll see right away that replacing it is a tricky operation at best.

Luckily, there are professional services to step in. Life Pixel Infrared Conversion is an industry leader and does an excellent job of converting cameras—whether point-and-shoot or D-SLR. Alternatively, the company will sell you the new filter so you can do it yourself. Life Pixel also has some clever alternatives that mix visible light and infrared to provide what it calls "Enhanced" infrared. The autofocus and metering work correctly almost all the time, although sometimes a little exposure compensation is needed—after all, the meters are designed for visible light, not infrared.

I carry a Nikon D70 that Life Pixel converted, so it is an easy matter to grab it and shoot infrared. The infrared conversion lets me take these photographs without a tripod, even capture sporting-event shots or other motion images. The resulting images are tack-sharp, and the ease of use really makes it fun to shoot in infrared rather than visible-light mode. —next: Processing your Images >

Processing your Images

Infrared images take some extra work once you get them onto your computer. The first thing you'll need to do is color-balance the image; it will often start out looking very red. The simplest way to do that is with the Convert to Black and White command in Photoshop or Photoshop Elements. (While it's possible to create "false color" infrared, the overwhelming majority of infrared photography goes for a classic black-and-white look.) You can adjust how the colors are mixed, using the sliders, until you get your image looking the way you want.

Infrared images also tend to look a little flat. Simply adding a Levels adjustment layer and moving the Black Point and White Point sliders in toward the image data on the histogram will help your image pop. Finally, your image is also likely to appear a little blurred. There are a few reasons this tends to happen. First, the focusing mechanism used to capture visible-light images isn't entirely suitable for capturing images in the near infrared spectrum, so it is easy to have the focus slightly off. Using a smaller aperture helps with this, of course. Also, because the light coming into the camera is way off the red end of the spectrum, your green and particularly blue pixels aren't receiving much light, so the image needs to be interpolated mostly from the red pixels. As a result it has a bit less detail than a visible-light image and can appear to be slightly blurry.

You can use the Auto Sharpen command in Elements or an equivalent sharpening command in other image-editing software to fix that. From here you can tweak the image to suit your tastes—in the sample landscape image I painted out the cars and used Nik Software's Color Efex to add a photo print look using the Photo Stylize filter and a fancy edge with the Vignette filter—but even without any fancy effects your image is ready to go.

Check out our slideshow of infrared images and editing techniques.

For more photography tips, check out How To Shoot Snow With Your Digital Camera on Appscout.com.

This article originally appeared on PCMag.com.