EXPOSURE AND EXPOSURE DEVICES 



245 



Table XXII gives basic exposures when the illumination is from photoflood lamps. 



Tables for Color Motion-picture Photography. — Table XXIII gives basic exposure 

 data for color motion-picture photography in daylight, whereas Table XXIV gives 

 similar data for photoflood illumination. 



Table XXI. — Exposures for Black-and-white Motion-picture Photography 



IN Daylight 

 (Weston Rating— 24 to 48) 



Table XXI gives suggested exposures for black-and-white motion-picture photography using day- 

 light illumination. It is calculated for the following conditions: 



1. Light Values. — For unity (1) light values as given in Table IX. For latitudes and times of the 

 day and year for which the light value is not unity, multiply the aperture given in Table XXI by the 

 square root of the light values given in Table IX. 



2. Film Speed. — Calculated for films having a daylight speed of Weston 24 to 48. For conversion 

 for other film speeds, 



multiply /-number by 0.15 for Weston speeds between 0.6 and 1 . 2 



" 0.25 " " " " 1.5 " 3.5 



" 0.4 " " " " 4 " 8 



" 0.6 " " " " 10 " 20 



" 1 " " " " 24 " 48 



" 1.5 " " " " 64 " 128 



" 2.5 " " " " 150 " 320. 



3. Time of Day. — To within 1 hr. of sunrise and sunset for panchromatic materials; to within 2}i hr. 

 of sunrise and sunset for orthochromatic materials. 



