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An "Average Eye" For Heterochromatic Photometry, and a Comparison of a ...
E. C. Crittenden
No preview available - 2016
1.2 wpc tungsten 114 observers 2.5 millilamberts 20 observers 25 meter-candles accuracy average eye calibration cent concentration cent difference change in transmission characteristic ratio cm Cells color blind comparison effective brightness equality fields equality of brightness equality photometer equality-of equality-of-brightness measurements equality-of-brightness photometer equality-of-brightness settings established eter experienced observers field Small field flicker curve flicker instrument flicker values given groups of observers groups of readings higher Ilium illumination of 25 indicated individual characteristics Ives and Kingsbury laboratories lamps operated Large field Small large number large-field equality lumens per watt luminosity mean residuals mean result meas median ments Middlekauff normal values number of observers paraffin photom photometer head photometric field practically present prism repeated results obtained selecting observers servers spectrum systematic difference systematic errors Table temperature tion tometer Trans Transmission of Blue vacuum tungsten lamp variation watts per candle wpc carbon lamp wpc tungsten lamp yellow test solution