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1945 Theatre Catalog, 4th Edition, Page 585 (557)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 585
Page 585

1945 Theatre Catalog, 4th Edition, Page 585

which can operate at a much higher power. (2) The development of the projection optical system. The maximum efiiciency appears to have been reached that is possible by straight pros jection by lens, but great improvement has been effected by RCA and others using a mirror projection system, and much work is now being done with a view to developing further types of optical system to increase the light efiiciency. And (3) the design of a special television screen for the stage to make better use of the light projected on it. Some screens have been developed both in Germany and England, where the light received by the screen is refiected back not all over the theatre, as in the case of the standard matte white screen, but concentrated directly into the seats of the auditorium. Much more efiicient screens are, therefore, possible and the brightness to the individual observer in any seat may be in this manner increased three or four times.

It is likely, however, that we shall arrive at a limit in cathode-ray-tube projection systems which will even then not provide a picture as bright as the cin FIGURE 8.-Here is a back-stage, close-up view of Scophony/s 12-foot screen installed at the Odeon Cinema, in London's Leicester Square, in 1939. In the picture can be well seen the manner of handling the spezial loudspeakers required for delivering television sound to the theatre audienze.


Also note the manner in


ema requires. The ultimate projector of electronic type is envisaged as a type of light valve as described above. (Figure 9.) A device of this type should not be restricted as regards illumination and brightness of picture on the screen, but so far only very imperfect results have been obtained with a device of this nature. The idea was put forward by various. investigators, for instance, by V. Zworykin; by J. L. Baird, under the name Diavisor; by A. H. Rosenthal of the Scophony company, in the Skiatron tube; and also by J. S. Donal and D. B. Langmuir, who have proposed and demonstrated a light valve consisting of suspended opaque particles which are oriented under the infiuence of an electron beam to form an image which could be projected. Thus, we are faced in pure electronic methods by an extension of the present cathode-ray-tube projection system, which appears to have limitations, and by various theoretical proposals which have so far not been jus tified by practical experiment but which

many believe will provide the ultimate form for cinema projection. Some authorities still believe in the

future of the above-mentioned intermediate film system, whereby a television signal is impressed on the photographic film which is rapidly processed and then projected in the theatre. We have seen good results by this method, and we are able to obtain a permanent film record in the theatre itself of the pictures thrown on the screen, but the majority of engineers have faith in the development of a full electronic system to which the intermediate film method can be applied as an adjunct whenever it is necessary in the theatre to make a permanent record of the projected programs.

The possibilities presented by the before-mentioned AFIF system of Zurich, must also be borne in mind in considering future lines of development.

Installation of Equipment

So far, equipment has not been produced which enables the television picture to be projected from the booth. Equipment has either been installed in the center of the auditorium (either in the middle of the orchestra or at the

which the screen is hung and laced on a wooden frame which can be raised into the fly left when it is necessary to reset the stage for the continuation of the cinematographic portion of the program. At the extreme right of the picture can be seen a battery of three flood lights which is part of this well-equipped stage.
1945 Theatre Catalog, 4th Edition, Page 585