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1954-55 Theatre Catalog, 12th Edition, Page 274 (238)

1954-55 Theatre Catalog, 12th Edition
1954-55 Theatre Catalog
1954-55 Theatre Catalog, 12th Edition, Page 274
Page 274

1954-55 Theatre Catalog, 12th Edition, Page 274

Wide Screen Light Requirements

An Analysis of the Light Requirements Necessary in Order to Project the Various Wide Screen Systems Satisfactorily

That the wide screen is here to stay is confirmed by the policies and commitments of major film producers to release their future better pictures either in CinemaScope or VistaVision processes. With a blessing on these two systems given by most, if not all of the film producers, the exhibitor can proceed to equip his theatre with reasonable assurance that the equipment he purchases will be suitable for the projection of whatever wide screen system may eventually prevail.

Increased Screen Illumination

Those theatres that have already equipped for CinemaScope have learned whether or not they have ample screen illumination on the basis of their screen size. Theatres that have not as yet installed a large screen and may or may not have suitable projection lamps can approach the problem of solving their light requirements from two anglesfirst, that of determining how much light they will need to project a picture of the size which they intend to install; or second, determining how large a picture they can present with their present projection arc lamps. With both wide screen systems of projection with their vastly increased screen area there is a general requirement for more screen illumination than has been necessary heretofore.

As the matter of film apertures and aspect ratios has been pretty well established for these systems, it is possible to

Aperture Size

CinemaScope-nnumorphic magnetic sound

CinemnScope-lnamorphic optic-1 sound

CinemaScope -an-morphi c

magnetic sound .912 x .715

.912 x .715


Engineering Vice-President Strong Electric Corp.

BRIEF: Since the introduction of the various wide screen forms 0/ film presentation there has been a great deal of confusion as to the types of screens . . . lamps . . . aperture plates . . . etc. . . . needed in order to get the proper amount of illumination on the screen . . . This article is a summary of the various wide screen systems now in use . . . and an analysis of the light requirements . . . The feature covers CinemaScope . . . VistaVision . . . drive-ins . . . and many other areas of importance to the exhibitor . . . In addition . . . there is an interesting section devoted to the comparison of the light requirements of the diferent systems . . . Prepared in a simple straightforward fashion, . . . this article should help clear up much of the misunderstandings regarding light requirements for the wide screen, systems.

present a few facts and comparisons from which conclusions can be drawn that will obviate a period of expansive experimentation.

THIS CHART offers much valuable information about the requirements for wide screen systems.

Aperture Lumena Type of Are: thru Screen sq. in. Aperture



It is generally recognized that the maximum amount of light that can be put through present projection systems using present designs of powerful arc lamps and optical systems depends principally upon one factor, the area of the aperture. For instance, using the most powerful lamps, it is usually possible to put about 6500 lumens through a 16mm aperture. Using the same lamp it is possible to project approximately 23,500 lumens through a 35mm aperture, which has about four times the area of the 16mm aperture.

Since the amount of light which is available to the screen depends primarily upon the area of the picture aperture, to compare the requirements of the various projection systems it becomes necessary to examine them on an aperture area basis.

Most of the wide screen systems proposed use either an anamorphic type lens to expand the size of the picture or use a cut down aperture to accomplish the extended picture ratio, For instance, the non-anamorphic VistaVision system makes use of an aperture which is .825 inch wide (the same as the standard motion picture aperture which has been in use since the advent of sound) by .446 inch in height. These. dimensions give an aspect ratio of 1.85 to 1 to the picture when projected with a non-anamorphic lens. This aperture has an area of .368 square inch.

Picture Screen width

Aspect Size Ratio

Ratio h ft. lamberts Factor Center

l lust-Vision non-anamorphic .825 x .lilib 17,500 matte white

Vista-Vision non-lnamorphic .825 x Jill/3 17,500 lluminized 1.85:1 CinemaScope-annmorphic optical sound .839 x .715 .600 28,500 matte white 2.35:1 92 x 39 1.30

31,000 100 x VisteVIsion-anlmorohic .825 x .600 23,500 aluminized 102 x 51

.839 x .715 m 28,500 aluminized 31.000

1954-55 Theatre Catalog, 12th Edition, Page 274