Hurter and Driffield actinograph 2nd model

Made:
1893-1903 in London
maker:
Hurter and Driffield

Wooden slide rule type calculator for exposure. Flat wooden plate marked with 3 scales. Speed 0.5-300. Exposure 0.005-60seconds. Lens f/2.8-64. Slide marked with weather: Very dull, dull, mean, bright, very bright. With speed index mark. Card insert carries time of day and year scale for North latitude 7 degrees and 30 foot. Hurter and Driffield. c.1898.

Details

Category:
Photographic Technology
Object Number:
1990-5036/3860
Materials:
cardboard, felt and wood (unidentified)
type:
actinometer
credit:
The Kodak Collection at the National Media Museum, Bradford