01069 Dresden, Germany
In 1902 Walter studied at Technische Hochschule in Dresden, Germany.
Walter Koenig was educated at Leipzig University in Leipzig, Germany, and the Technische Hochschule in Dresden, Germany receiving from the latter an engineer's degree in 1902 and a doctorate in 1903.
After graduation Koenig worked as a chemist in the Farbenfabriken vorm Friedr. Bayer & Co. in Elberfeld, to1908. Also, he served as an assistant at the Technische Hochschule in Dresden, Germany from 1906 to1908, when he became a special instructor there. From 1913 to 1945, and from 1949 to 1957, Koenig was a professor of color chemistry and dye technique at the Hochschule, also assuming the directorship of the laboratory of color and textile chemistry in 1926.
During 1922-1924, Koenig devised an improved method of preparing carbocyanine spectral sensitizers for photographic emulsions. From 1924 to 1925 Walter Koenig described the indocyanines and the preparation of quinoline. In this year he patented a method of preparing dicarbocyamnes that are efficient as deep-red and infrared sensitizers, and he proceeded to develop polymethine dyes for sensitizing photographic emulsions for infrared - a spectral field invisible to the human eye. These emulsions are valuable in the photography of distant scenes, penetration of mist and fog, and aerial photography.