. Transactions of the Society of Motion Picture Engineers (1921). Fig. 7. Light Beam in Motion Picture Projection using Plano-convex Condensersand No. 2 Objective Lens. rays than the plano-convex condensing lens system, which is placedat a greater distance. Therefore the initial utilizatioTi of the lightwith the prismatic condensing lens system must be greater. Onaccount of the closer spacing of the prismatic condensing lens to theaperture, the light rays pass through the aperture in a wider sphericalangle than when plano-convex condensing lenses are used. Figures6, 7, 8, 9, illustrate the abo
. Transactions of the Society of Motion Picture Engineers (1921). Fig. 7. Light Beam in Motion Picture Projection using Plano-convex Condensersand No. 2 Objective Lens. rays than the plano-convex condensing lens system, which is placedat a greater distance. Therefore the initial utilizatioTi of the lightwith the prismatic condensing lens system must be greater. Onaccount of the closer spacing of the prismatic condensing lens to theaperture, the light rays pass through the aperture in a wider sphericalangle than when plano-convex condensing lenses are used. Figures6, 7, 8, 9, illustrate the above statements very well. This will accountfor the greater additional amount of light that can be gained byselecting the correct size of objective lens. By using a No. 2objective lens (2^ diam.) in place of a No. 1 objective lens (l^diam.), when the prismatic condensing lens is employed, an increaseof from 50% to 80% in sci-een illumination may be obtained (Fig,. Fig. 8. Light Beam in Motion Picture Projection using Prismatic Condenser andNo. 1 Objective Lens (showing light lost with small diam. objective). 173
Size: 2012px × 1242px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsocietyo, bookcentury1900, bookdecade1920, bookyear1921
