THE FIELD OF VISION FOR COLOURS 



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 



Wave-lengths 42'4 620'8 607 '8 601 '3 595'3 589'3 584'2 



Minimal-field 

 luminosities 66'6 91'5 112'8 128 110'9 100 90 



Wave-lengths 579' 1 574' 1 564'8 551 '4 



Minimal-field 



luminosities S1'6 79'5 68-fi 52 



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



~2 18 16 1,1 12 1 0,8 0,6 O.i 0.2 CU 0.1 0.6 0.8 1 1.2 1,1 1.6 1,8 2 2,2 2.t 2.6 2s 3 3.^ 3.4 i6 3g 4- 



**:: 



O 

 CO 

 O 

 VO 



s 



of 



(O 

 IO 



in 



I 



IT) 



CN 



10 



Fig. 27. 



" Minimal-field luminosity curve." Photopic 



periphery luminosity curve. Photopic central luminosity curve 



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



(Siebeck.) 



