MOTION-PICTURE PHOTOGRAPHY 



677 



Modern motion-picture negative film is generally manufactured with a gray back- 

 ing or base to reduce halation. The principal cause of this defect, which manifests 

 itself by halos surrounding bright lights in the scene, is reflection of light from the base 

 back into the coating. While films having a thin base are less liable to this trouble 



2.20 

 2.00 

 1.80 

 1.60 

 1.40 

 1.20 

 1.00 

 0.80 

 0.60 

 0.A0 

 Q20 



2.20 

 2.00 

 1.80 

 1.60 

 1.40 

 1.20^ 



1.00 "i 



Q60 

 0.40 

 Q20 



8 



10 



12 



2 4 6 



Minu+es 

 -Time-gamma curve of Eastman duplicating positive, No. 1355. 



Fig. 20£. 

 3.80 

 3.60 

 3.40 

 3.20 

 3.00 

 2.80 

 2.60 

 240 

 220 



:^2.00 

 w 



£ 1.80 

 o 

 1.60 



1.40 

 1.20 

 1.00 

 0.80 

 0.60 

 0.40 

 0.20 

 



1.05 0.05 1.05 2.05 



Log Exposure 



Fig. 20C. — Z)-logio E curves of Eastman duplicating positive No. 1362. 



than plates for a given size of image, the motion-picture frame size is so small that the 

 effect is disturbing with a clear base. The gray base provides an effective remedy. 

 Sometimes this preventive layer is interposed between the base and the emulsion. In 

 either case it merely requires an increase of 1 to 1.5 points in printing. 



