Proceedings of the British Kinematograph Society (1936)

the practice in one large studio indicated that many times diffusers’: were used to cut intensity rather than to alter the quality of the light. Bis BeBe | | | a | @ [| : B pf [| [| [| [| |_| a & ta | | || a Be |_| iS | & a | | | | [| [9 ih ¢ if It 1a H gz Figure 8 Although it is recognised that this is often necessary, yet as a general practice it should be discouraged, certainly if a number of light sources are used, because of the necessity of different requirements from each source. If the total intensity is found to be too high, it would be much more desirable to use sources of a lower wattage rather than to dissipate the excess of light by using diffusers. In the particular studio in question it was found desirable to mark the Junior Solar Spots with distinguishing marks and instal in a certain number of these spots 1,000 watt lamps. A number of these lamps were always mounted on the spot rail and on the floor when the set was rigged. A great saving in wattage was made by changing to 1,000 watt lamps if the 2,000 watt intensity was too high. Inside Frosted Lamps Another efficient means of securing diffusion is the more generally used inside frosted lamps. There is not the loss of efficiency with the inside frosted lamp as with the cello glass or silk diffusers. It is, of course, realised that there will always be special requirements which cannot be covered in a general discussion. However, close observation indicates that not enough attention has been given to the great loss of energy caused by careless use of diffusers. Filters The subject of filters opens up a very interesting, almost untouched, field which is open to the more studious cameraman who wants to weigh the colour temperature of his light sources against the film emulsion which he is using. I have already pointed out the desirability of having light sources of the same colour temperature. If a cameraman starts out with a light source of a known colour temperature he can then experiment with variations in this colour temperature to secure results which will be both interesting and effective. This is most evident in lighting for colour photography where it is possible to secure warmer tones by using unfiltered incandescent lamps in conjunction with pat a coo anreitae serosa a austen ume L aes a ~~ aa TH ee rene imme comes B |G = neSSeS an S ae HH oe mB Zz B re) x R & Figure 9 arc lamps. <A splendid example of this will be seen in the picture ‘‘ Dancing Pirate,’’ which will be released shortly. The use of filters is one of the easy ways to change the colour temperature of