Speaking Light in Tone and Color: What might the camera sensor have in common with Optics, written by Ptolemy in Egypt in the 2nd Century AD?
When considering the physical construction and in describing the performance of camera digital censors I first think of the neo-impressionistic artwork of painters, such as, Georges Seurat and Paul Signac. Unlike conventional painting were colors are mixed (customarily on a pallet) before application to a canvas, their technique was based on optical mixtures. They practiced a separation of colors called divisionism, and their application of individual colors was named pointillism.
They based their approach on the scientific writings on color theory and optics by Eugene Chevreul and Odgen Rood. Chevreul’s writings on color in the early 1800’s greatly influenced painters by including in the color scheme process how our minds interact with and perceive colors, but Rood is of particular interest to me as a photographer, in that he valued photography’s primary colors of red, green, blue, and alerted artist to note that material pigments do not mix the same way as do optical (light) pigments.
The reason for this fresh approach to painting was the view that applying paint in this way, so the viewer can blend the colors optically, gave the appearance of more brilliant colors and a more shimmering of light from the canvas. I see the correlation of this approach to the camera’s digital sensor.
The camera’s digital sensor works on through the optical blending of the primary colors, red, green, and blue. When speaking of resolution or dpi (dots per inch), be it on the camera sensor or computer screen I again find a correlation to pointillism, as these artists used varying colored dots per inch to create their art. And in the end, results so viewed are bright and colors brilliant. Compare these results to those photographs shot on film in the past and converted to prints by chemical tray and inkjet printer, or even digital photographs made by the latter a.k.a Giclee method, the brightness and brilliance of those results are always somewhat diminished by the blending methods inherent in these processes
Artistic connections to the digital camera sensor can be made ever farther back in time to the first mosaic art expressions created millenniums ago. This art form takes squares of colored stones or glass that are of the similar proportions, which are placed side by side in patterns depicting subjects, similar as done in pointillist paintings. Seen at a distance this pattern of colored squares optically blend to create the fluid scenes we are accustomed to.
It is thought that the Egyptian scientist, Ptolemy, in his treatise “Optics” written in the 2nd Century AD may in part have been influenced by mosaic art in outlining two causes of optical fusion, the confusion of images as a result of distance and motion.
On a recent trip in taking photographs of scenic Utah I consistently experienced both causes. With distance, if a sunlit bush was close in my camera frame I could easily distinguish subtle tones and hues, while the same tones and hues at a distance became more optically fused, that is more uniform and blended. Taking photographs from a moving vehicle, which caused motion blur of closer subjects, also resulted in optical blending, although it was less apparent in tone.
The interesting aspect in considering the relationship of the camera’s digital sensor to other art forms on the historical timeline is to underline and emphasize that it is completely depended to the physiology of human vision, and seldom, if ever, is this apparent in discussions. In capturing photographs all the concerns, investigations, explorations of photographers and their trade magazines seem revolve around scientific advances and algorithms in camera sensors, while little attention is ever given to observations over the physiology of sight. And in the end, be it with our eyes or in unison with our camera’s sensor, shouldn’t there be a comprehensive look at light and lighting, which makes all seeing possible? Too much is taken for granted and certainly this should not be path in mastering photography.