British Kinematography (1947)

42 LECTURES ON OPTICS TN response to requests from the B.K.S. and members of the industry, the Polytech^ nic, Regent Street, is organising a third refresher course to follow those being held at present on " Sensitometry and Laboratory Praciice "and" The Fundamentals of Sound Recording." The subject asked for is " Optics " and the lecturer is Malcolm V. Hoare B.Sc. The course is intended for those engaged in all branches of the film industry who use lenses or other optical equipment and find that an understanding of the be haviour of light would help them in their work. The course will consist of 10 lectures to be held on Monday evenings from 6-8 p.m. at the Polytechnic, commencing on Monday, 14th April. The fee for the course will be £1 and students should enrol at the Polytechnic on or before that date. Outline Syllabus 14th April Light and the Spectrum. Units of light measurement. 21st April Recording of colour in monochrome. Filters. 28th April Pola screens. Exposure meters. Measurements of light. 5th May Basic laws of optics. Image formation. 1 2th May Lens systems and focusing. 19th May Perspective. Factors affecting the length of an image. 26th May No lecture. 2nd June Depth of field and depth of focus in theory and practice. 9th June Errors of lens systems. Coated lenses. 1 6th June Basic types of lens systems. Lens testing. 23rd June Optical systems used in film industry. J BOOK REVIEWS PHOTOELECTRIC CELLS by A. Sommer {Methuen's Monographs on Physical Subjects). Methuen, 5s. net. 100 pages, 27 Figs. There is no question as to Dr. Sommer's ability and qualification to write a monograph on photo-cells, as he has been engaged on their development at Cinema-Television for many years. This is an excellent book and summarises the theory and practical points on cells in a very readable manner. After the historical introduction, the theory of photo-electric emission is explained with the minimum of mathematical expressions, followed by a long chapter on the manufacture and properties of photo-cathodes. The chapter on matching light sources and cathodes, i.e., choosing a cell, is of interest to every user of these universally (but often wrongly) used electronic devices. The comparison between the gas-filled cell and the vacuum cell is also of particular interest, as is the comparison between the multiplier cell and the plain cell. The final chapter on the applications can only summarise the principal points, but there is a table giving the types recommended for various applications, and the reader is referred to other books dealing with this aspect more fully. The kinematograph engineer who takes more than a passing interest in the electronic gadget on which his livelihood depends should make a point of buying this book at the very reasonable price of 5s. G. Parr. SOCIOLOGY OF FILM bv J. P. Mayer. Faber and Faber, Ltd. 328 pages. 15s. J. P. Mayer has written here a philosophical treatise both ambitious and erud te. It consequently follows that there is a challenge on every page, and enough material for a brains trust to disagree over for an inordinate number of sessions. It is, indeed, the author's search for esoteric motives for things that can be explained far more simply that is the factor likely t o provoke most opposition. " Why do millions go to the picture house ? " he asks in his first paragraph, and quotes psychologists as answering that our modern populus seeks escape from the dreariness and mechanisation of our rationalised lives. But one might equally ask, " Why reading ? " " Why music ? " " Why the arts ? " " Why a deck chair on the beach ? " Is not the short answer this : " Because we enjoy it " ? He quotes appreciatively another author as saying : " The Elizabethans