. Transactions of the Society of Motion Picture Engineers (1921) . Figure 3 This is shown diagramatically in Fig. 4, where Pj, Pg and P. are the locations of the light source, Sj, S2 and S3 the distances of the light sources from the slide D^, D2 and D3, the distances of slide to screens H^, H2, H3, the respective heights of the pictures and «!, flo ^^d flg the angles subtended by the Fig- 4—Diagram showing the two methods of obtaining a larger picture. When the first method is used the average illumination of thesame size picture will be less than by the second method, since thesubten
. Transactions of the Society of Motion Picture Engineers (1921) . Figure 3 This is shown diagramatically in Fig. 4, where Pj, Pg and P. are the locations of the light source, Sj, S2 and S3 the distances of the light sources from the slide D^, D2 and D3, the distances of slide to screens H^, H2, H3, the respective heights of the pictures and «!, flo ^^d flg the angles subtended by the Fig- 4—Diagram showing the two methods of obtaining a larger picture. When the first method is used the average illumination of thesame size picture will be less than by the second method, since thesubtended angle is constant and distance to the screen increases inthe first case and the distance to the screen is constant and the sub-tended angle greater in the second case. (Fig. 5). 50 On the other hand, however, better definition should be obtainedby the first method since the farther away the Hght source from thesnde the nearer it approaches the hypothetical point source of lightcondition. (Fig. 5).
Size: 1973px × 1266px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidtransactions, bookyear1921
