Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 148
spects of thisquestion. The sharpness or definition of ashadow does not depend altogetheron its actual density. The gradient ofthe density of the shadow at the edgeshas a marked effect on its visibility,and is an important factor from thepractical standpoint. This gradient ofdensity in turn depends… … 20 40 60 10 80 20 100 }2<) .^0 14(1 10 Kill 50 ISli liO 20 1 220 240 2H0 FlO. 18.—Distribution from (1) hire lamp, andsame lamp ia (2) acid etched (3) snud-blasted(4) opal globes respectively. of illuminating engineering can readilywork out the resulting illuminationwhen the lamp is placed at a…
Lighting
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
