264 



TABLE 310. 



Tables 3lft-311. 

 PHOTOGRAPHIC DATA. 

 Photograpbic Efficieocies of Various Lights. 



Source. 



Sun 



Sky 



Acetylene 



" (screened) 



Pentane 



Mercury arc, quartz 



" " "Nultra" glass.. 



" " crown glass 



Carbon arc, ordinary 



" " white flame 



" " enclosed 



Carbon arc, " Artisto" 



Magnetite arc 



Carbon glow-lamp 



Carbon glow-lamp 



Tungsten vacuum lamp 



" vacuum lamp 



" nitrogen lamp 



" nitrogen lamp 



" blue bulb 



" blue bulb 



Mercury arc (Cooper Hewitt). 



Visual 



efficiency. 



Lumens 



per 



watt. 



150 



0.7 

 0.07 

 o 04s 



40 



35 



37 



12 



29 

 9 



2.44 

 3.16 



8 

 9.9 

 16.6 

 21.6 

 8.9 

 II 

 23 



Photographic efiiciency. 



(a) 



Ordinary 

 plate. 



100 

 181 

 30 



600 

 218 

 324 

 126 

 257 

 175 

 796 

 106 

 23 



25 



33 

 37 

 56 



— 

 108 

 316 



Ortho- 

 chromatic 

 plate. 



100 



155 



44 



8S 



28 



500 



iQS 



275 



112 



234 



177 



1070 



"5 



32 



35 



41 



45 



62 



68 



99 



354 



(A) 



Pan- Ordinary 



100 

 130 

 52 

 89 

 42 

 367 

 165 

 249 

 104 



215 



16s 



744 

 82 

 42 

 45 

 SO 

 53 

 70 



I5 

 106 

 273 



o. 14 

 0.037 

 O.OS3 

 158 



50 



79 



10 



52 



II 



62 



12 

 0.37 

 0-5I 

 1-74 

 2.41 

 6.1 

 8.9 

 5-5 

 7-8 



47 



Ortho- 

 chromatic 

 plate. 



o. 21 

 0.040 

 0.086 

 132 



46 



68 



10 



45 



II 



86 



14 

 0.52 

 0.74 

 2. 2 

 30 

 6.8 

 9.8 

 5-2 

 7-3 

 54-2 



Pan- 

 chromatic 

 plate. 



100 



o. 24 

 0.042 

 0.13 



99 



39 



62 

 8.5 

 2.0 



10 



60 



(a) Relative efficiencies based on equal illumination. 



(h) Relative efficiencies based on equal energy density. 



Taken from Jones, Hodgson, Huse, Tr. 111. Eng. Soc. 10, p. 963, 1915. 



TABLE 311. — Relative Intensification of Various Intensifiers. 



See Nietz and Huse, J. Fraaklin Inst. March •?, iqiS. 



• B. J. Almanac, see annual Almanac of British Journal of Photography. 



t B. J. refers to British Journal of Photography. 



Smithsonian Tables. 



