THE FIELD OF VISION FOR COLOUES 



73 



these circumstances and found that these " minimal field luminosities " 

 agree with both the ordinary and the peripheral photopic luminosity 

 curves, and therefore disagree with the achromatic scotopic luminosity 

 curve. He found the maximum luminosity by this method at 601*3 fifj. : 



90 



The minimal -field and luminosity curves are shown in Fig. 27. 



■—I — I — I — I — I — I — I — I — I — I — I — I — I — I — I I 1 — I — I — I — I — 1 — I — I — I — I — I — I . 



~2 1,8 1.6 1,1 U 1 0,8 Q6 0.1 0.2 0,2 0.<. 0,6 0,8 t 1.2 XH 1,6 1.8 2 Z'J. 2.t 2,6 Zs 3 3.2 i.t i.6 i& ^ 



h 



o 

 co" 





I 



5_ 



ID 



I: 



J: 



in 



CM 



iT) 



3. 



o 



Si 



Fig. 27. "Minimal-field luminosity curve." Photopic 



periphery luminosity curve. — Photopic central luminosity curve 



(flicker method) " Il'-curve " of a deuteranope (see Fig. 45). 



(Siebeck.) 



