> > > >

1954-55 Theatre Catalog, 12th Edition, Page 21 (xxi)

1954-55 Theatre Catalog, 12th Edition
1954-55 Theatre Catalog
1954-55 Theatre Catalog, 12th Edition, Page 21
Page 21

1954-55 Theatre Catalog, 12th Edition, Page 21

distribution on the quality of the projected image with a view toward improving existing or future screen brightness standards.

Exhibitors who are interested in a high level of technical efficiency are able to compare performance in their own theatres with the norm and with the Society's recommendations. Producers can learn in detail how their films are being shown; film laboratories now have up-to-date information on current viewing conditions that should have value in the preparation of release prints; equipment manufacturers can learn more than they now know about actual performance of their equipment in service.

Another of the engineering committees having to do with the theatre matter, the Film Projection Practice Committee, is improving the standard which determines the height at which the projector lens should be set, measured from the projection-room floor. The same standard also prescribes focal lengths and focal markings for projector lenses.

Tes'l' Films

A very comprehensive selection of test films is put out by the Society in collaboration with the Motion Picture Research Council. In design, test films are the yardsticks for setting performance objectives of new equipment. In production they are standard tools of inspection. As a uniform source of film signal

for lining up the film pickup system, they aid in proper mechanical adjustment of the projector and its sound reproducer mechanism.

There are films that tell what is wrong when the projector or sound system is not operating correctly. Others are for use after repairs, while adjustments are being made, and indicate when performance is again within specifications. There are test films with picture and sound, of typical release print quality, that make individual or comparative demonstrations of projectors meaningful.

Recently the Society took over the distribution of test films for CinemaScope also. Included among the films available are: a level balance film used in adjusting all channels for equal volume, a multifrequency test film used for checking the frequency response of all four channels; a flutter test film accurately made to measure variations of the rate at which the film passes through the magnetic reproducer; .a loudspeaker phasing test film which carries a warble frequency signal to check the phasing between the high-frequency and low-frequency speakers on channels one, two and three; constant level test film with an accurately placed 8000 cycles per second recording to check azimuth of the

SCENE FROM A TYPICAL KINETOPHONE sound production. This one was "After College Days."

magnetic reproducer heads; a channel four test film consisting of a recording of 12,000 and 1000 cycle signals to adjust the automatic switching circuits on the channel four surround speakers; and a projector alignment test film containing picture only, used in adjusting the projector aperture plate, positioning of the anamorphic projection lens attachment, the alignment of one projection machine with the other and for positioning the black masking around the screen.

Work in Progress

In the changing conditions of the last couple of years, and faced by new and unprecedented competition in the entertainment field, the motion-picture business has been stirring itself as it has rarely been stirred since the pioneer days. New color systems, new lighting methods aiming at a more satisfying projected picture in conventional theatres and in the new drive-ins, wide-screen techniques and 3-D have all been the subject of vigorous experimentation, with varying degrees of success. The distinguishing feature of most of these efforts has been their dependence on longestablished principles and standards. Research engineers have delved back into the archives, come up with promising lines of inquiry from the remote past of the industry, and set to work to develop them to meet the needs of the present.
1954-55 Theatre Catalog, 12th Edition, Page 21