Kinematograph year book (1939)

292 The Kinematograph Year Book. The Maximum series were the leaders of the short-back focus types which have now found favour amongst all manufacturers, and the Ultimum series are outstanding for their corrections for colour combined with maximum screen brilliancy. The 1938 C.E.A. Exhibition evidenced that Taylor-Hobson were well to the front in the development of lenses for television projection for large screens, and the many demonstrations of large-screen television given at the Tatler Theatre have been given with the help of these lenses. The 14-in. lens of exceptionally large aperture represents a decided step forward in the development of large-aperture long-focus projection lenses. Walturdaw Cinema Supply Co., Ltd., handle complete projection range of Zeiss lenses which vary in foci from 40 mm. at F.-1.9 aperture, to 200-mm. focus at the aperture of F.-1.9. They are able, therefore, to cater for a complete range of lenses that could possibly be required in any kinema. Of special note are the kipronar series of from 120 to 200 mm. focus which have a constant aperture of F.-1.9 and vary in diameter between 80 to 100 mm., and the new Alinar series of short focus length lenses. CARBON PROGRESS. The growing consciousness among exhibitors of the importance of screen brightness has caused them to welcome the researches being carried on by various carbon manufacturers to perfect the development of a more reliable and economical source of projection ilium inant, particularly in respect to the production of the A.C. high-intensity carbon. Special attention has also been directed, of course, to the various projection problems arising from the increasing use of colour in films. In this connection it is of interest to note that the Morganite Reflectometer referred to upon another page, which was introduced at the close of 1937, made vast strides during the year, and is now widely used — it is no exaggeration to say that nearly all premieres and Trade shows of important colour films are now prepared with this instrument. The mass of data obtained with it by the Morganite service engineers has been placed at the disposal of the Committee which is considering the question of standardisation. Early this year a paper read to the Royal Photographic Society by Chas. H. Champion, F.R.P.S., M.I.M.E., A.M.I.E.E., gave the results of the researches of the Strip Carbon laboratories into the development of the high intensity A.C. arc. He claimed that the correct design and loading of the carbons has almost eliminated the typical A.C. nicker, and asserted that the idea that the bulk of the light emanated from an incandescent ball of gas was quite fallacious. His contention was substantiated by a novel method, which included the translation of the polar curves into their visual equivalents by means of a Kodachrome film, taken both at normal and super-normal speeds. Ship Carbons. — The introduction and development by Ship Carbons during 1937 of the Suprexa carbon was a logical progression from the Suprex in the direction of achieving the highest efficiency in the light source for projector purposes. That the Suprexa did, in fact, supply the required increase in general reliability and economy expected of it, is proved by the fact that orders for this type of carbon have taxed the production of the Chadwell Heath factory to the full. Thus over some seven years Ship Carbon engineers, producing in sequence the Hilo, the Suprex, and the Suprexa carbons, have acquired an experience in the direction of small diameter high intensity carbons which is both unique and highly valuable. It was with this experience as a basis, in fact, that they were enabled to produce the modern A.C. high current density carbon to which they have given the trade name of Alternalux. The advantages in operating convenience and economy offered by this type of carbon are becoming more widely appreciated each week in the kinema field, as is shown by the rapidly increasing number of orders for Alternalux carbons.