Nature photographers' clothing and gear color really matter!

Birds typically have sharper vision, and significantly superior color vision than humans. Birds can see certain light frequencies, including ultraviolet, which are invisible to most humans.

Their superior eyesight can diminish the nature photographers’ ability to get closet to birds, desirable to help photographers make sharp, detailed images of these beautiful feathered animals.

Nature photography has five keys for success I call “Wildlife Photography's Five P's”: Preparation, Practice, Patience, Persistence, Propaedeutics.”™ This article concentrates on “propaedeutics,” learning connected with any art or science. The more we learn about wildlife as photographers the more successful we can be making wildlife images.

Learning about avian eye physiology helps bird photographers understand how bird’s superior vision affects the photographers’ ability to make great images of birds, thus aiding them in maximizing their bird photo opportunities.

Like the human eye, the avian eyes use rods and cones to see. Rod and cone cells are photoreceptors, specialized neurons which perform “phototransduction,” converting light into electrical signals sent to the brain for interpretation as vision.

Rod cells are more sensitive to light than cone cells. They are mostly responsible for night vision. Rod cells are “monochromatic,” having only a single pigment type. Rod cell vision is primarily grayscale and has little, if any, role in color perception.

Human cone cells are trichromatic, basically red, green and blue photoreceptors, though each cone has sensitivity to a small range of light wave lengths centering around red, green and blue. By combining these colors additively, as is done with computer monitors, our eyes are able to see millions of colors.

Unlike human cone cells, avian cone cells are tetrachromatic. Like human cones cells, birds have red, blue and green cones, and in addition, have a UV (ultraviolet) cone. Ultraviolet light is a shorter wavelength light than most humans can see. By seeing ultraviolet light birds can see fluorescence.

In addition, to the four types of cones, birds have double cones. Researchers have suggested double cones are used achromatically by birds to improve their vision of luminance, motion and polarized light, but at this time, their precise function is unknown.
In addition to double cones and ultraviolet cones, birds have another enhancement which improves their color visual acuity compared to human eyes. Birds' cones have clear or colored oil droplets, shown in the illustration above, which can filter out high-energy lower wavelengths’ potentially harmful effects, and enhance birds visual contrast and color discrimination abilities.

There are other advantages which bird eyes have over human eyes.

The density of cones in the retina of birds is generally far in excess the their density in humans retinas; from two to five times more. Nocturnal birds, have fewer cones than other birds, but many more rods for their night vision. Owls with their large eyes and high density of rods, have as much as 100 times the light sensitivity of humans.

Avian eyes have a different method of supplying nutrients and oxygen to the retina via blood, than the human eye. Human eyes have blood vessels which lie in front of the retina, causing some shadows and light scattering, which diminishes vision acuity. Bird eyes use the “pectin,” shown in the illustration of a bird eye to the left. The “pectin” is a comb-like structure of blood vessels extending in the eye, supplying nutrients and oxygen to the retina, which causes no shadows and light scattering in bird eyes.

So, how does bird “super vision” affect bird photography?

Most photographers interested in shooting wildlife have heard the term “Circle of Fear.” Animals, like humans, have a natural area around them in which they sense danger and become more and more fearful as potential predators get further and further inside that circle. As people approach animals they will typically watch as we get closer, and become gradually more wary and fearful, to the point they will either flee or attack. That area is the animal’s “circle of fear.” The size of the “circle” is variable, depending on the animal’s general nature, and its attitude and circumstance at that particular moment; aggressive, timid, hungry, injured, protecting offspring, etc.

The larger the “circle of fear” the further away from the animal the nature photographer will first be noticed, then tracked. Once noticed, as the photographer moves deeper into the “circle of fear,” tangentially within it, or even remains almost motionless once inside, the more likely the animal will stop its typical behavior, replacing it minimally with wariness of the photographer, and eventually hide or flee.

With enhanced visual acuity, contrast and color discrimination, and the ability to see ultraviolet light, birds are able to easily distinguish potential predators, including photographers, from their surroundings, within larger “circles of fear” than would otherwise be possible.

Birds especially notice brightly colored clothing popular today. Reds, oranges, bright yellows, greens and blues quickly catch the attention of birds. White in a forested area in summer will be conspicuous. Neon colors are striking to birds due to their ultraviolet visual abilities. To birds, any neon colored clothing will make photographers literally jump out of their background. Carrying around gear in neon or brightly colored backpacks, such as those flashy “Nikon yellow” bags can be seen “miles away” by bird eyes.

Even some camera gear can be problematical for nature photographers. Colorful cameras in bright reds and blues, or ones with shiny reflective metal are more easily seen by birds than more traditional black, and non-reflective camera bodies.

Photographers wishing to make images of birds and other animals should try to blend into their surroundings wherever they are.

Most of the time that means photographers should wear neutral colors such as tans, grays, and pastels, to mitigate the effects of birds excellent color vision. Light greens and browns are good, and washed out jeans are fine. While “camouflage” clothing isn't necessary, it works well to help the photographer blend in with their background.

Note: When in Arctic or snowy conditions, for example, the photographer’s choice of color should often be different than in the forest, or green meadows. White works well in snowy conditions or against many sand beaches.

Wherever they’re shooting nature photographers should cover cameras which are brightly colored with a neutral, black or camouflage protective cover. The same is true of lenses. Canon telephoto lenses, with their characteristic off white and black rings are an example of lenses which would benefit from being covered. Cameras' and lens' highly reflective surfaces should be covered. For small surfaces, gaffer's tape may suffice.

Finally, the contrast of the human face, especially the Caucasian face, to its surroundings can be particularly striking, especially when accentuated by bright clothing. Hats in neutral or pastel colors are a must to break up the human face outline, and cover the head's noticeable color contrast with the photographer's surroundings. A wide brimmed hat, with the brim circling the head is best, but even a neutral or pastel colored baseball type cap is better than nothing.
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Credits for images:

Great Blue Heron at the John Heinz National Wildlife Refuge: Copyright © 2014 NSL Photography, All Rights Reserved

Avian Eye Cone Types: Copyright © 2013 Corbo Lab, Washington University in St. Louis School of Medicine, Dept of Pathology

Anatomy of the avian eye: Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.

Circle of Fear of Male Wood Duck at the John Heinz National Wildlife Refuge: Copyright © 2014 NSL Photography, All Rights Reserved