Panchromatic

Description

However, his technique was not extended to achieve a fully panchromatic film until the early 1900s, shortly after his death. Kenneth Mees credits Wratten & Wainwright with preparing the first commercial plates with panchromatic emulsions. Panchromatic stock for still photographic plates became available commercially in 1906. The switch from orthochromatic film, however, was only gradual. Panchromatic plates cost two to three times as much, and had to be developed in total darkness, unlike orthochromatic—which, being insensitive to red, could be developed under a red light in the darkroom. And the process that increased the film's sensitivity to yellow and red also made it oversensitive to blue and violet, requiring a yellow-red lens filter to correct it, which in turn reduced the total amount of light and increased the necessary exposure time.