American cinematographer (Jan-Dec 1926)

E «hteen AMERICAN CINEM ATOGR APHER May, 1926 PROJECTION (Continued from Page point /. In the event that during the time that the film has moved from point / to 2, the mirror c maintains its former position Jx. If the mirror, however, turns and takes up the new position 2, then the projection on the screen also remains stationary in the point f and the film movement is thus optically compensated. The same is true, if the frame and the mirror take up the respective positions 3 and .?'. At this moment at the point / appears the following picture whose movement will be compensated in the very same way. For this purpose the mirror c has another rotatory motion round the axis h, besides the above mentioned swinging motion and leaves the bundle of light rays behind as soon as it has come in the position of 3\ A second mirror follows it and takes the position /', which was originally occcupied by the first mirror and goes the same way, that is first occupying the position /' like its predecessor and ending in position 31. Hereby is the movement of the second frame compensated. This goes on till 8 sector mirrors have made a full circular motion round the axis //. A suitable wheelwork between the axis // and the film sprocket wheel k (see Fig. 2) works in such a way that a complete correspondence exists between the movement of the film and the compensating arrangement. "Because the mirrors follow each other without any gap, it happens that with every change of picture, for a time, parts of two sector mirrors, are at the same time in the bundle of light rays. The one mirror is compensating the movement of one frame whereas the second mirror has already begun the compensation of the following frame and so it happens that with every transition of a picture on the projection screen, the projection of two frames which follow each other occurs at the same time. The process goes, forward in such a manner that during every change of picture the mirror which is leaving the field gets less and less light and the mirror which is just entering the field gets more and more light so that the illumination of both the pictures which cover each other on the screen is continuously changing. Their total illumination however remains the same. One projected picture is thus replaced by the next following without the dark interval and the change of pictures corre GOERZ Negative Raw Stock Now Key Numbered MORE GRADATION; MORE DEFINITION; NO GRAIN SOLE DISTRIBUTORS: Fish Schurman Corporation 45 West 45th Street 1050 Cahuenga Avenue New York City Hollywood, Cal. IN CANADA: JOHN A. CHANTLER & CO. 200 Bay Street, Toronto, Ont. Roy Davidge Film Laboratories The Little Laboratory with the Big Reputation 6701 SANTA MONICA BLVD. HOLLYWOOD 1944 Ar h IfALTLt J VAN ROSSEM 6049 Hollywood Blvd. Phone Holly 725 Commercial Photogi^phy Still Developing and R-intin^ fcHoiaCamaas-FOR. RENT— Still **