Reality is so subjective. The visual universe we have painstakingly theorized, observed and transcribed throughout a few millennia of evolution (sic) is only real to our very biased human eye-brain combo.
Many so-called realities logically co-exist, then, likely as many as there are sentient beings, each group having its own adaptation. Honeybees see into the ultraviolet band. Our feline and canine friends only have limited color vision, their reality already departing from ours. Dolphins and whales see no color whatsoever, a universe of nuanced whites, blacks and all in-between gray shades. And what about E.T., the Fremens and H.A.L. 9000? For each a different definition of what is real.
Our human eyes, no matter how extraordinary a trichromatic1 design, only perceive a fraction of electromagnetic radiation which we have labeled light. Within that light spectrum, we can only interpret a narrow subset, thus named “visible”. The colors most of us see are due to those visible waves being reflected by matter.
Beyond the lower edge of that reflected light lies the infrared spectrum (IR). Its longer waves appear just below our visible red color, and while it seems non-existent to us, IR is perfectly usable for technological purposes such as night vision and remote controls.
Photography, it turns out, can also toy with the infrared spectrum. Out of the box, our digital cameras are actually designed by manufacturers to render reality as we see it, so they aggressively block infrared and ultraviolet light. In most cases, a “hot filter” is placed in front of the sensor for that purpose. But intentionally removing that filter allows a camera sensor to record the full light spectrum; this is called a full spectrum conversion in photogeek terms.
A converted camera then sees too many clashing realities if left as-is and must use situation-specific filters to render one or the other: a visible light filter, or “IR/UV cut”, restores a camera’s original capabilities; infrared filters, on the other hand, allow only the IR spectrum through. There are multiple IR filter types, each with slightly different wavelength filtering.
So make no mistake about it, when using an infrared-converted camera and filters to render the images in this post, I am not exactly showing you an infrared universe, since our eyes cannot perceive it. What I am doing instead is recording it in a raw form but based on a white balance2 I determine to be appropriate (already skewing its reality towards what I appreciate for mine) and then developing the results to taste. It is in no way what an infrared-adjusted being would see, but rather my arbitrary shifting of an invisible world towards mine.
With that out of the way, the possibilities are endless and infrared photography opens the gate to a new universe, one never seen before and yet as real as anything else we can imagine. It is an art form, of course, and as such subjective and opinionated. And that’s why I like it.
Out of camera, a raw infrared file looks a bit like an old film negative; dark reddish and brown tones, odd purples, and some elements our logic refuses to identify. For the most eye-pleasing results and white foliage, a color channel swap can be done in post-processing, shifting reds and blues to the opposite of their respective value. This restores blue skies, a staple of our acceptable reality, while preserving much artistic freedom. But why white trees and vegetation, you might ask? And why not, I would answer. Our green is arbitrary. Foliage reflects the most infrared light, appearing white in the IR spectrum if white balance is set for it.
But some filters let more visible light through than others and can yield mesmerizing candy-like or fiery hues. Sometimes, it’s even fun to bring everything down to blunt black and white, a creative mingling of Ansel Adams and Frankenstein.
So here is a world of shifted hues and subtle tones, of summer snow and pale flowers. It is—almost—the infrared realm.
1. In very simplified terms, trichromats such as humans and some animals have three types of eye cone cells and thus three color channels to convey color. Cats and dogs are dichromats with only two kinds of cones, and other animals are monochromats and only perceive light intensity but no color.
2. Setting a white balance means telling the camera (or later the editing software) what element in a scene should be white, based on existing lighting conditions. Most cameras can do this automatically, albeit not always too accurately. A manual white balance can be set by measuring light on a white or neutral gray object, or a gray card.
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Brigitte
Vince