702 handbook of photography 



Positive Developers 



Formula D-16 



Water 750 . cc. 



Elon 0.31 g. 



vSodium sulphite (desiccated) 39 . 6 g. 



Hydroquinone 6.0 g. 



Sodium carbonate (desiccated) 18.7 g. 



Potassium bromide 0.86 g. 



Citric acid . 0.68 g. 



Potassium metabisulphite 1.5 g. 



Cold water to make 1.0 1. 



The chemicals in the D-16 formula are to be dissolved in the above order. The 

 replenisher differs somewhat from the composition of the original mixture, prin- 

 cipally in that it contains twice as much sodium carbonate and half again as much 

 hydroquinone. 



Formula PD-2 



Water S75.0 cc. 



Rhodol (metol or Elou) 1.7 g. 



Sodium sulphite (anhydrous) 67 . 5 g. 



Hydroquinone 8.5 g. 



Sodium carbonate (monohydrated) 26.0 g. 



Potassium bromide . 75 g. 



Final volume 1.0 1. 



Numerous other phases of motion-picture laboratory practice are outside the 

 scope of this chapter. These include preferred layouts for laboratory buildings; 

 fixing, washing, and drying; reduction and intensification; reclamation of silver from 

 exhausted solutions; printer maintenance; storage of film; preservative treatment of 

 finished prints; inspection, etc. For material on these subjects the reader is referred 

 to the bibliography at the end of the chapter and especially to the Report of the Com- 

 mittee on Laboratory Practice of the Society of Motion Picture Engineers, and the 

 Eastman book on "Motion Picture Laboratory Practice." 



Process Photography. — The term "process photography" includes a variety of 

 special effects, such as the making of dissolves, fades, and wipes, as well as more com- 

 plex forms of scene-to-scene transitions of the montage type; the making of titles; 

 reduction of 35-mm. films to substandard sizes; the improvement of faulty negatives 

 by optical methods; providing backgrounds for studio production; trick shots of all 

 kinds, usualljr involving matting, multiple exposure, etc.; combinations of photographs 

 of real people and animals with photographs of cartoons or puppets; combinations of 

 photographs of scenic paintings with photographs of real people, animals, and sets; and 

 combinations involving the use of miniature models. Some of these effects may be 

 secured in a standard motion-picture camera, either by itself or equipped with simple 

 accessories like bipack magazines, but the majority require special apparatus, such as 

 animation stands, optical printers, rear-projection equipment, etc. Moreover, the 

 technique of process photography is so involved that normallj'' it cannot be applied 

 readily to day-by-day production activities and is better left for "aftertreatment," 

 which affords the additional advantage of allowing preliminary editing of the picture 

 before final decisions are made on what effects are to be employed and where they 

 shall be inserted. 



Composite photography as a means of supplying backgrounds has greatly extended 

 the range of dramatic production and at the same time reduced expense, since it is 

 usually cheaper to bring a scene to the studio photographically instead of transporting 

 cHst, company, and equipment to a distant location. It makes possible effects which 

 could not be secured without prohibitive difficulty or danger in the field. Actuallj'' at 



