HARRISON & HARRISON LIGHT CORRECTOR METER ( COLOUR TEMP) FROM 1947 MADE FOR HOLLYWOOD FILM INDUSTRY
Harrison & Harrison made photographic filters back in the 1930s, 40s and 50sand this handy litle device was made in 1947 for the Hollywood film industry. A lovely slab of metal and bakelite, complete with a faux-leather case, this is an interesting photographic collectible.
This meter is approximately 4 inches in diameter. It's a thick disc with two spinning calculator dials, one on each side. Along the outer edge of the meter there are a series of view holes (barely visible here) and each one has a different filter. The idea is you view the scene through this meter and judge which one looks best. The dial only exposes three filters at a time, so the calculator can tell you what you're looking at. One side tells you the color temperature of the scene in degrees Kelvin, and then suggests the proper Harrison color corrector filter to use for the kind of film you've loaded. In this case the scene reads 4800K, so if you're using Daylight film, you'd use a Harrison B½. Flip the calculator over and tells you how to compensate exposure. In this case, a B½ requires 3/4-stop of additonal exposure.