Has someone ever asked you why you like an image? Beneath the surface of great picture, there is a geometric design in hiding. During World War II, photographer Alfred Eisenstaedt worked for the early version of the Associated Press and went on to become a Life Magazine photographer, taking over fifty cover shots for them. Without getting too deep into Eisenstaedt’s personal story, I will say that he started photography with very little formal training.
Want to focus your camera simply by looking at a particular area of the viewfinder? If you’re a Sony shooter, you might be enjoying that feature as early as next year. The company is reportedly working on building Eye Tracking autofocus into its cameras, with the initial version arriving in a flagship camera sometime in 2014.
This article started after I followed an online discussion about whether a 35mm or a 50mm lens on a full frame camera gives the equivalent field of view to normal human vision. This particular discussion immediately delved into the optical physics of the eye as a camera and lens — an understandable comparison since the eye consists of a front element (the cornea), an aperture ring (the iris and pupil), a lens, and a sensor (the retina).
Despite all the impressive mathematics thrown back and forth regarding the optical physics of the eyeball, the discussion didn’t quite seem to make sense logically, so I did a lot of reading of my own on the topic.
Using the human eye to control cameras isn’t a new idea — Canon used to offer eye-controlled focusing in its SLRs — but designer Mimi Zou‘s Iris concept camera takes the concept one step further by having the camera be entirely controlled by the eye. Shaped like a lens, the photographer uses the camera by simply looking through it. Focusing, zooming, and snapping photos are done by looking, narrowing/widening the eyes, and blinking (respectively).
Ever wonder what the f-number of your eyes are? It can easily be calculated using the human eye’s focal length (~22mm) and physical aperture size. Here’s what Wikipedia has to say:
Computing the f-number of the human eye involves computing the physical aperture and focal length of the eye. The pupil can be as large as 6–7 mm wide open, which translates into the maximum physical aperture.
The f-number of the human eye varies from about f/8.3 in a very brightly lit place to about f/2.1 in the dark. The presented maximum f-number has been questioned, as it seems to only match the focal length that assumes outgoing light rays. According to the incoming rays of light (what we actually see), the focal length of the eye is a bit longer, resulting in minimum f-number of f/3.2.
The article also notes that the eye cannot be considered an ordinary air-filled camera since it’s filled with light refracting liquid.
F-number: Human Eye (via Reddit)
Image credit: eye 172/365 by attila acs
Image sensors and the advent of digital imaging have been met with differing reactions from the photographical community. But what a team of doctors at the Oxford Eye Hospital have managed to do with the technology is 100% digital, and 100% amazing. Clinical trial leaders Robert MacLaren and Tim Jackson have helped two blind men to partially see again. Read more…
After taking a macro photograph of his own eye using a Samsung WB500 compact camera, Jarroseph was startled to find that the photograph showed his own face reflected in his eyeball. His face had reflected off the front of the lens, off his eyeball, and then into the camera!
(via Reddit via Photojojo)
Image credit: Photograph by Jarroseph and used with permission
You may have heard that digital cameras can be made sensitive to infrared light by removing the IR filter found inside, but did you now that something similar can be done with the human eye? People who have aphakia, or the absence of the lens on the eye, have reported the ability to see ultraviolet wavelengths. Claude Monet was one such person. Carl Zimmer writes,
Late in his life, Claude Monet developed cataracts. As his lenses degraded, they blocked parts of the visible spectrum, and the colors he perceived grew muddy. Monet’s cataracts left him struggling to paint; he complained to friends that he felt as if he saw everything in a fog. After years of failed treatments, he agreed at age 82 to have the lens of his left eye completely removed. Light could now stream through the opening unimpeded. Monet could now see familiar colors again. And he could also see colors he had never seen before. Monet began to see–and to paint–in ultraviolet.
[...] With his lens removed, Monet continued to paint. Flowers remained one of his favorite subjects. Only now the flowers were different. When most people look at water lily flowers, they appear white. After his cataract surgery, Monet’s blue-tuned pigments could grab some of the UV light bouncing off of the petals. He started to paint the flowers a whitish-blue.
The lens on a human eye ordinarily filters out UV rays, so we don’t see many of the things certain animals see. For example, the males and females of some butterfly species look identical to the human eye but very different to UV-sensitive eyes — the males sport bright patterns in order to attract the females!
Monet’s Ultraviolet Eye (via kottke.org)
Want to see how your eyes stack up against other photographers when it comes to seeing colors? Try your hand at Color, a simple browser-based color matching game that tests you in how quickly you can match colors. It starts with simple matching, but soon moves onto more difficult challenges involving multiple colors. Be sure to leave a comment here reporting on the score you get!
Color: A color matching game (via Fstoppers)
Here’s a quick and simple tip for better portraits by Reddit user rmx_:
Everyone has a lazy eye. By that, I mean one eye is always smaller and/or more closed than the other eye. In some people, it is very easy to spot; in others, nearly impossible. The “beautiful people” have more symmetrical faces, but still, one eye will open more than the other. (Denzel Washington has one of the most I have seen [...])
[...] here is the tip: get the smaller/lazier eye slightly closer to the camera. Oh, and don’t tell the person what you’re looking at their eyes for! You’ll make them self conscious. Simply ask them to look at your finger and move their head to follow it, and then guide them left or right as necessary. Chances are, the movement needed will not be so much that you have to adjust your lights.
You can read more about how facial symmetry relates to beauty in this Wikipedia article.
Image credit: Man portrait by Yuri Samoilov