EXPOSURE AND EXPOSURE DEVICES 



247 



These calculators are usually designed for daylight and cannot be used for artificial 

 light unless special scales for artificial illumination are provided. The scales are 

 designed to take into account the various light conditions of the sky, type of subject, 

 film speed, time of day, time of year, and even geographic latitude. 



For a given amount of information, calculators are usually somewhat more compact 

 than tables and, since a particular series of settings may be obtained for a given specific 



Table XXIII. — Exposures for Color Motion-picture Photography in Daylight 



(Weston Ratings — 10 to 20) 



Table XXIII gives suggested exposures for color motion-picture photography in daylight. It is 

 calculated for the following conditions: 



1. Light Values. — For unity (1) light values as given in Table IX. If other light values apply, 

 multiply exposure apertures of Table XXIII by the square root of the appropriate light values given in 

 Table IX. 



2. Film Speed. — For films having a daylight speed rating of Weston 5 to 10. For other film speeds, 



multiply /-number by 0.25 for Weston speeds between 0.6 and 1.2 



0.4 " 1.5 " 3 



" 0.6 " " " " 4 " 8 



1 " " " " 10 " 20 



" 1.5 " 24 •' 48 



3. Time of Day. — To within 1 hr. of sunrise and sunset, unless sunrise or sunset photographs are 

 being made. 



