LIGHT SOURCES AND DETECTORS 



(A 



CM 



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 u 



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T3 

 O 



O 



C 

 (0 



c 

 E 



3 



0-0000000001 



0-000000001 



0-00000001 



0-0000001 



0000001 



000001 



0-0001 



0001 



0-01 



01 



1 



10 



100 



1.000 



10,000 



loaooo 

 ipoo.ooo 



10,000,000 



- } 



- } 



Visual threshold 

 after dark adaptation 



White surface lit by 

 moonless night sky 



White surface lit 

 by moonlit sky 



Read newsprint 

 with difficulty 



Comfortable 

 reading 



Adequate for 

 finest visual task 



•"Candle flame 



I Luminance of white paper 

 i in full sunlight 



Freezing 

 •- Platinum 



, Tungsten 

 lamps 



} 



Compact source 

 Mercury lamps 



Sun 



A-Bomb first 

 1 three millisecs 



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 g 



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O 

 QC 



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> c o 



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Figure 28.1 



AOO 



500 600 700 



Wavelength - ^ my. 



Figure 28.2 Luminosity curves for scotopic {rod) vision O — O 

 and phot opic (cone) vision • — •. 



334 



