Web work 3

Orthochromatic Film Is only sensitive to blue and red light. Making blue objects lighter and red objects darker.

"Orthochromatic films were first produced by Hermann Wilhelm Vogel in 1873 by adding small amounts of certain aniline based dyes to photographic emulsions which had hitherto been sensitive to blue light only, work that was extended by others including Josef Maria Eder, who introduced the use of the red dye erythrosine in 1884" (taken from Wikipedia)

http://www.youtube.com/watch?v=JaT3g20nXF8