Edwin Herbert Land (May 7 1909 – March 1 1991) was an American scientist and inventor. Among other things, he invented inexpensive filters for polarizing light, instant polaroid photography, and his retinex theory of color vision.

Biography

Early years

Born in Bridgeport, Connecticut, he studied chemistry at Harvard. While still a freshman, he invented the first inexpensive filters capable of polarizing light. Edwin Land did not finish his studies, but instead set up the Land-Wheelwright Laboratories in 1932 together with his Harvard physics instructor.

Land then went on to establish the Polaroid Corporation in Boston in 1937 to further develop and produce the sheet polarizers under the Polaroid trademark. The initial major application was for sunglasses and science, but it has found many applications, for instance as an important component of LCDs. On February 21 1947, Edwin Land demonstrated an instant image camera and associated film. Called the Land Camera, it was in commercial sale less than two years later.

Later years

In the 1950s, Edwin Land's team helped design the optics of the revolutionary Lockheed U-2 spy plane. Also in this decade, Land first discovered a two-color system for projecting the entire spectrum of hues with only two colors of projecting light (he later found more specifically that one could achieve the same effect using very narrow bands of 500nm and 557nm light). Some of this was written up later in the 1970s with his Retinex theory. In 1957 Harvard University awarded him an honorary doctorate. Later a street in Cambridge, Massachusetts, closer to MIT's campus than to Harvard's, was named after him.

In the early 1970s, he attempted to explain the previously known phenomenon of color constancy with his Retinex theory of color vision. His popular demonstrations of color constancy raised much interest in the concept. Land however failed to cite earlier work on the concept and was later criticized for that. In his retirement years, he founded the Rowland Institute for Science.

External links

• Excellent biography
• Short biography

Patents

• US2435720 -- Apparatus for exposing and processing photographic film