Nipher — Relation of Direct to Reversed Photographic Pictures. 55 



Diagram I. 



E 



zero eonflition 



ic 



a 



3000 



2000 







in 



<r 



LC03 



d 



I 



o TTT1 ^~T 



7 3 5 4 3 



0.2 



2.5 



I 



2 r 



Ordinates represent exposure in lamp-meter-seconds. Lamp = 16 candle 



power. 

 Abscissae represent illumination of the plate while in the developing bath, 



in lamp-meters. 

 The rectangular area within the zero line, covers the conditions yielding 



negatives. External to this line is the region of positives. 



