Optical Density

 


The relative darkness of an image in a finished film is called simply density.

Photographic density for film is determined by measuring the incident to transmitted light ratio and expressing the value as a logarithm

Density (D) = Log (Intensity of Incident Light / Intensity of Transmitted Light)

For example if 100 is the intesity of the viewing bow and 10 is the value transmitted through a film the film density = Log (100/10) =1

(Fuji Ltd)

 

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