Handbook of projection for theatre managers and motion picture projectionists ([1922])

Record Details:

Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.

Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.

300 HANDBOOK OF PROJECTION FOR light in the projector optical system, as well as to make impractical the maintenance of maximum sharpness in focus of the picture. The only advantages of such a location are ease of ventilation, ease of taking care of smoke in case of fire, ease of sound-proofing and cheapness of installation. In other words it barters high-class screen results for cheapness of installation and ease of operation. The front-of-balcony location costs more to install, but Should give an almost ideal projection distance. If properly installed its fire dangers are purely imaginary, its thorough ventilation entirely practical and it may be depended upon to provide a projection angle well within the permissible limit. Special projector tables, Fig. 81 A, will automatically take care of displacement of picture through sag of balcony under load. The main floor location is entirely practical, from any and every viewpoint. Its only legitimate objection is that it is more costly of installation, and reduces seating capacity, though in the long run it may be depended upon to produce quite sufficient revenue to more than compensate for the seating space it occupies. The following may be considered as the essentials of a first-class up-to-date projection room: (A) It must be so located that a point central between the two projector lens ports will be exactly centered with the center of the screen sidewise, and its height above the center of the screen must be such that the distortion of the picture will in no cases exceed 5 per cent, of its normal or undistorted height. (B) The minimum distance of the projectors from the screen should be such as will call for the use of a projection lens of not less than 4-inch E-F. Anything less than this focal length will make it either very difficult, or impossible to secure sharp definition all over the screen without reducing the working opening of the projection lens, which means loss of light. On the other hand the distance from the lens to the screen may be as much as 250, or even 300 feet, though we would advise against such an attempt and very strongly recommend that the projection distance be kept within a maximum of 75 or at most 100 feet, since long projection distance means loss of light in the optical system and more or less tendency to lack of sharpness in the picture through inability of the projectionist to see it clearly. (C) The projection room must be absolutely fireproof,