The Magic of Lighting in Photography

This video, which is apparently a trailer for a music video rather than a documentary about the power of lighting in photography, is absolutely fascinating:

If you take pictures, or even just look at pictures, it is worth watching this video in full because it shows you just how powerful the effect of lighting is.

Part of where lighting gains its power, by the way, is that our brain does an enormous amount of processing on the images it gets from the eyes. Not only does it remove the blood vessels and the blind spot in front of our optic nerve from what we perceive based on its knowledge of what it is that it’s looking at (the origin of many optical illusions), it also does color correction.

We’re used to thinking of an object as having a color based on what light it reflects but this is only partially true. A red ball does, in fact, absorb green and blue (etc) and only reflect red, but the light which reaches our eyes is dependent on what light hits the ball. In white light, the standard description of color more-or-less applies. But in, for example, blue light, no light comes back from the ball and it looks black. In red light, the same amount of red light comes back from a red ball as comes back from a white ball, so the white ball looks red. Or, depending on how our brain decides to interpret it, the red ball looks white. That’s the basis of those secret messages which were printed in blue against a red squiggly background. In white light the squiggles dominate our ability to see images, but in red light (usually achieved by using red cellophane as a filter) the red squiggles look no different than the white paper and so disappear, while the blue text which was the same brightness (in white light) as the red squiggles now show up as black.

There’s all sorts of interesting tricks which can be pulled off with light, too, because the red, green, and blue photo-receptors in our eyes are not equally sensitive. Green seems the brightest to us, so you can make the colors of, for example, tropical fish pop more by illuminating them with lights that have a lot of red and blue but not much green; thus the amount of red and blue which reflects off the fish compared to the overall brightness is higher and they look more colorful (this is why they always look better in the pet store unless you invest in the special lights for your home aquarium—on the plus side those lights are better for aquarium pants, too).

There are similar considerations when lighting people with little pigment in their skin. Light which has too much red in it can easily make their skin look very reddish.

There’s another curious effect which is that the overall quantity of light will change things because every photo-receptor (whether in a camera or an eye) has a maximum amount of stimulation. If you can use so much light that you can exceed the maximum amount of stimulation, you can “wash” the colors out as everything tends towards white since the relative balance of colors changes. You can use tricks like this to lighten or darken someone’s skin in a photo shoot, for example.

Cameras don’t like by commission, but they lie by omission all the time.

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