566 



HANDBOOK OF PHOTOGRAPHY 



Physiologically there is an advantage in the OA even if it is adjusted, by distance, 

 so that it gives less illumination on the paper. Contrasts appear greater in red light 

 than in yellow or green. The apparent contrast of a print under the yellow-green light 

 of the OA is more nearly the contrast under daylight than if the series O is used. 



Relcji+ion of Safeligh-I- 

 Color +o Paper Sensi+ivi+y 



Azo, Ad Type, 

 A+hena 



Safeligh-I" 

 Series 00 



I Yellow 



Opal, Projec-hion 



PMC, News 



KodoiJine, 



Bromide 



Soi-Feligh + 

 Series 



Safeligh+ 

 Series OA 



juwKktit, 



I I I 



iOMKU 



I I I Red 



J L 





Green 



Kodali+h 

 Or+ho 



Safeligh+ 

 Series 1 



Insurotnce 

 Bromide 



So(-Feligh+ 

 Series 2 



Viw4l^^ 





, I Deep 

 I ■ Red 



Fig. 4. — Safe lights to be used with Eastman Kodak papers. 



Therefore, with Velour Black, or any projection paper which has any sensitivity 

 in the red, e.g., chlorobromides, it is better to work in the yellow-green light of the 

 Wratten OA safe light, even if the illumination is less than with the series O. 



Trays and Tanks. — Trays are universally employed for developing prints and 

 are very often used for processing negative materials. Trays may be made of steel 

 which has been enameled, or of stainless steel, hard rubber, glass or pyrex. In emer- 

 gencies kitchen dishes may be employed. If need arises for a tray of special size 

 or dimensions, it may be made of wood (or heavy cardboard) coated with a thick layer 



