Georgina Gonzalez, reporting for the Verge:
Most clinical photos are taken by well-intentioned doctors who haven’t been trained in the nuances of photographing patients of different races. There are fundamental differences in the physics of how light interacts with different skin tones that can make documenting conditions on skin of color more difficult, says Chrystye Sisson, associate professor and chair of the photographic science program at Rochester Institute of Technology, the only such program in the nation.
Interactions between light, objects, and our eyes allow us to perceive color. For instance, a red object absorbs every wavelength of light except red, which it reflects back into our eyes. The more melanin there is in the skin, the more light it absorbs, and the less light it reflects back.
But standard photographic setups don’t account for those differences.
One of the things that I routinely experience shooting street photography in a multicultural city is just how screwy camera defaults treat individuals of different racial backgrounds. And I’ve yet to find a single default that captures darker skin accurately despite shooting for many years.