Quote Originally Posted by Q.G. View Post
Just about, i'd say.

First efforts were orthochromatic, only blue (and a bit of green) sensitive.
Panchromatic emulsions began to appear, and became common, in the 1910s, certainly 1920s. Verichrome was introduced in 1931, as one of the new generation of panchromatic (!) monochrome films.
That misses out the bulk of films made between the early 1900's and WWII, many were made right up to the 50's. These were also usually the company's highest selling films.

Verichrome was never a Panchromatic film, neither version, Mees was involved with both the Wratten & later Kodak version, it was only replaced by Verichrome Pan in 1956. Kodak's equivalent speed (roughly) Pan film in the 30's was Panatomic.

In between true Orthochromatic (Blue/green sensitive) and Panchromatic are the sub class of films with extended (high) sensitivities to Green , Yellow and often bordering on reds, it's these that the big manufacturers called "chrome"

Some B&W Chrome films.

Wrattern & Wainwright - Verichrome, Allochrome
Kodak - Verichrome
Agfa - Isochrom
Ilford - Selochrome
Bauchet - Hyperchromw
Voigthlander - Bessachrom (made by Gevaert)
and there would be others.



Ian