CH. XII] LIGHTING THE PROJECTION ROOM 441 



would still be an advantage; but for ordinary magic lantern and 

 moving picture exhibitions total darkening of the room is unneces- 

 sary and undesirable. But for all projection it is a great advan- 

 tage to prevent any light from falling upon the screen except that 

 from the projection apparatus. The room should therefore be 

 tinted with some light-absorbing color. Nothing is better than the 

 brownish color of natural wood, such as oak or pine. If natural 

 wood is not used, the walls and ceilings can be tinted brownish 

 or olive. For decorations, rich, dark red, orange, green, and blue 

 may be used. Light orange, green, and blue reflect too much light 

 but the dark, rich colors give the pleasing effect without making 

 the room too light. 



For mixing these tints, if oil colors are used, much turpentine 

 should be employed to give a flat or dull finish, not a shiny or glossy 

 one. If the finish is shiny it will act like a mirror and give an 

 undesirable glare, and shine in the face of some of the auditors. 



605. Light in the exhibition room. For magic lantern and 

 moving picture exhibitions, the room should be light enough so 

 that the spectators can easily find their way about ; and after the 

 twilight vision is established, the spectators should be able to take 

 notes easily. 



If the room is finished and decorated with light-absorbing colors 

 and tints as indicated above, there is no danger of making the 

 screen images gray and dull from reflections from the walls and 

 ceiling. One has simply to guard against direct light shining on the 

 screen from a window or from a lamp. (For lighting a black-board 

 in a lecture room see fig. 240). 



606. Lamps for general lighting. The lamps to give the 

 needed light should be so arranged, and with such shades that: 



(1) They cannot shine directly in the eyes of the spectators; and 



(2) That they cannot send any of their rays directly upon the 

 screen. This is best accomplished by placing the lights along the 

 sides of the room or on the ceiling or both, and shading them so that 

 none of their light can extend directly to the screen. 



The arrangement sometimes used of a row of lights around the 

 screen is bad; for, while no light can reach the screen from them, 



