"Orthochromatic & Panchromatic Film - A Question of Values" Topic

Kodak print advertisement, c.1930

I found the ad shown above while researching orthochromatic film. All early photography suffered from distortions of value (light and dark scale), due to the difference in color response between the photographic emulsion and that of the human eye. Sometime in the early 20th century, additives to the emulsion resulted in a film (panchromatic) whose color response was closer to that of the eye.

The upshot of all this is that monochrome photos aren't a particularly valuable source when trying to match an exact hue; there are a lot of variables (film type, ambient light, exposure time, etc.) that usually haven't been recorded for a particular photo, and so cannot be properly be accounted for in determining a "matching" color.

I admit that I am not much of a photographer, so if anyone wants to chime in with elaborations, corrections, etc, please do.

Ron

P.S. This is the topic that got me thinking of it: TMP link

It is one of the reasons why people who use a B&W photo, especially an orthochromatic photo as evidence for a particular shade or uniform color are kidding themselves.

An amusing example of this is the film "Night in the Museum." Theodore Roosevelt's collar, epaulettes and cuffs on his Rough Rider uniform are dark blue in the movie, and look that way in the photos the costume designer no doubt consulted. However, we know they were yellow, the cavalry branch color -- the photo emulsion of the period just made them look dark, almost black.

Same reason that French and British roundels look reversed in photos of WW1 aircraft.