Unseen infrared light can be likened to radiation, something we don’t see but feel, such as heat on our skin in the summer sun.
Digital camera sensors record more light than humans can see. When using an infrared filter, it captures infrared “radiation” and makes it visible to the eye. Normal light is blocked and infrared light passes through the filter.
Basic equipment for IR photography
Your camera should accept filters, either by attaching one directly to the lens or using a lens adapter.
Depending on your camera, you may need a tripod. Long exposure times are generally required for IR photography so hand-holding a camera isn’t recommended.
Composing infrared shots
Since an IR filters blocks all visible light, you won’t be able to see a thing when the filter is attached to the lens. First mount your camera on a tripod, next compose your photo and then attach the filter.
Digital camera settings for infrared photography
If you don’t make any camera adjustments when using an IR filter, images will be completely red. To get some of cool looking color effects, adjust the white balance setting. After attaching the filter, point the camera on sunlit green grass or a piece of white paper to take a manual white balance reading, and then take the shot.
Don’t totally judge IR photos by reviewing them on the camera LCD as they may appear flat or dark. Images will look better when viewed on a computer monitor and can be tweaked when edited.
It’s important to note that most digital cameras have a built-in infrared blocking filter that blocks the infrared light you want to capture. The built-in filter varies from camera to camera so some may produce strange colors.
Exposure times using an infrared filter
Most of the time the camera will be able to expose well enough to get good shots. You may need to increase the exposure value a few steps. Experiment by taking photos with varying exposure times or bracket.
Exposure times primarily depend on the effectiveness of the built-in IR blocking filter. Some digital cameras have a less effective blocking filter so exposure times can be short enough for hand-held shots. Generally, exposure may need to be increased to around 30 seconds.
Blur and noise in infrared photos
Because long exposures are often necessary, there can be motion blur and noise in the image. Photographers who shoot infrared often consider these affects desirable.
To keep noise at a minimum, shoot on bright days and use low ISO numbers. Shooting on a bright day will result in smaller apertures being used, with a benefit of increased depth of field.
Best subjects for infrared photography
The most popular subject for infrared photography is landscapes. Try to find a scene with some nice trees with white foliage and a bluish sky. There should be little breeze, if any at all. to prevent motion.
Have fun and experiment though.
Take infrared pictures of everything you see including still lifes. Different materials will either absorb or reflect infrared light and result in varied and interesting visual effects, though sometimes things can look bizarre.
Don’t forget to take infrared photos of friends and yourself. But because a long exposure may be needed, people generally don’t make the best subjects unless they can remain near-motionless while the shot it taken. Be forewarned, people photographed with an IR lens can look ghoulish.
Editing infrared images
Infrared images do not usually require special editing, but you can change the color effect. For example, swap the red and blue channels if you want images to have a blue sky instead of brown.
This article and photos were contributed by Jonas Förste.
For more information about infrared digital photography, check out these infrared FAQs.