Infrared: The World of Invisible Light

Today’s Post by Joe Farace

Vision is the art of seeing what is invisible to others. —Jonathan Swift

Ultra Violet (UV) light comes from the Sun but the Earth’s ozone layer protects us from most of this light. Many photographers keep UV aka Haze filters on their lenses as protection but they can also reduce the amount of ultraviolet radiation striking the image sensor or film plane and suppress atmospheric haze or dust. When photographing at high altitudes of 14,000 feet or more, you need a UV filter in front of your lens to be able produce the same color correct view that your brain send to your eyes.

And so we come to infrared: Astronomers have long used the infrared spectrum for astrophotography of distant non-terrestrial subjects but there are plenty of terrestrial applications for infrared photography too, including forensic investigation and aerial crop or forest surveys.

My personal philosophy is that photography should be fun. Part of having fun is trying new things. I find that digital infrared photography is lots of fun because it helps a person look at their world in a new way and lets them create images that are unlike any other technique that they’re likely to try. That alone, I think, is a good enough reason to try infrared digital photography.

How I Made this Photo: I photographed this sanctuary or mediation spot that’s located just off the bike path in McCabe Meadows, near Parker. Colorado. Those are not fall colors; this photograph was made in June! The image was made with a used Panasonic Lumix GX1 I bought from Roberts Camera and had converted to infrared capture with Life Pixel’s Hyper Color filter. The lens was an Olympus M.Zuiko 17mm f/2.8. Exposure was 1/200 sec at f/16 and ISO 400 Av mode. The RAW files was processed using one of Life Pixel’s proprietary Photoshop actions that were available when I had the conversion made.

A New World of Light

All light, visible or invisible, is a kind of wave and there are all kinds of invisible light, including radio waves, microwaves, infrared light, ultraviolet light, X rays, and gamma rays. Every photographer knows about visible light and what you see as red, orange, yellow, green, blue, indigo, and violet are really different wavelengths of light. Shorter waves are blue and the longer ones appear red to our eyes. Every color’s wavelength is measured in nanometers or one billionth of a millimeter or microns that are a millionth of a meter. Red light begins at wavelengths of about 0.65 microns. Violet light has wavelengths around 0.4 microns and yellow light waves are 0.6 microns. Your eyes can’t see light that have a wavelength that’s longer than 0.7 microns. When we feel the sun’s heat of the on our skin, we experience thermal infrared light

For the purpose of this blog and in my personal photography, light with wavelengths from 700 and 900nm are usually referred to as infrared light. You may be surprised to learn that this band of infrared light is a thousand times wider than that of visible light and yet is completely invisible to our eyes. Infrared film and some video cameras are sensitive to what is called “near infrared.” This is also the type of IR light that your television remote control *uses. Speaking of which…