The Bioscope (Jul-Sep 1931)

September 9, 1931 MODERN CINEMA TECHNIQUE THE BIOSCOPE iii PARKING PROBLEMS SOLVED Small Space Only — Cars Are Safe — Can Be Unpacked 51 Swiftly One of the greatest problems of the modern exhibitor is to provide or secure adequate parking accommodation for patrons who wish to come to the show in their cars. This is often a matter of very great expense and difficulty in theatres located in densely populated districts where ground rents are high. Sometimes the problem is solved by making arrangements with some nearby garage to house the cars of patrons at a nominal fee. But the arrangement is not satisfactory for several reasons. The garage is not under the direct control of the theatre’s management and the desired standard of courtesy cannot always be imposed ; the cost is often high and, finally, the fact that the garage is not actually attached to the premises is a serious draw-back. Cradles on Endless Chains With these difficulties in mind, the Westinghouse Company of America recently devised a new type of building which would occupy a minimum of floor-space and in which cars could be stored to an extent and with a simplicity never previously attempted. In this building there are no ramps or lifts in the ordinary meaning of the term and the usual army of attendants is dispensed with. The floor-space required is only that necessary for an ordinary two-car garage and Wide film appears to be stationary at the moment, but it is evident that there is a good deal of activity going on under the surface in connection with research. It is a mistake to think that no progress is being made. The matter has been arrested somewhat because of the difficulty of getting a general agreement on an ideal size for the “ wide ” screen picture. Opinion seems to be concentrating on 56 mm., but those mainly concerned with the Grandeur size are still convinced that the ultimate tendency will be towards the 70 mm. size. They claim that the proportion of the Grandeur picture, 2 : 1, is very close to the normal angle of vision. Any wide film will, however, present a series of new problems to the projectionist, and it is as well he should begin to give some thought to this. R. H. McCullough points out that these difficulties will arise very quickly in connection with short throws, when it is desired to obtain a picture of satisfactory width. At the present time, there are no lenses which can be secured under four inch equivalent focal length, which will give satisfactory results with Grandeur. Special Lens Needed An ordinary projection lens is entirely out of question, except in the longest focal lengths, because of objectionable curvature of field. It is necessary to use anastigmat lenses to obtain good definition, because of the wide angle. It is also necessary that the objective lens rear combination be of sufficient diameter so as to collect the area of light rays from the aperture — otherwise, loss of illumination will result at the sides of the projected image, which will be apparent by shadows. The better the definition of the Grandeur picture, the closer the front seats can be to the screen. If the Grandeur picture image is increased over fifty feet in length. can be built above ground to any required height — windows being unnecessary. The cars themselves are carried on cradles supported at each end on endless sprocket chains driven by electric motors. Each cradle is hung from its top at one end and from its bottom at the other, a form of suspension which permits side-sway but prevents swinging, thus giving great stability with entire freedom of movement. One Car Per Minute ! The control is on the same lines as that of an ordinary automatic elevator, the kind the passenger operates himself. But there is one big difference. In the case of a lift you have one car which has to be brought to rest at any one of several platforms. In the case of this vertical garage, the problem is to bring any one of a number of cages to rest on one platform at the road level. The system works very quickly and simply, the endless chain travels at the rate of about 100 ft. a minute so that the average time to bring any cage to the drive-away level is 30 seconds. Another 30 seconds are required for opening the door, driving the car on, or off, its cradle and closing the door again. There are three general ways of operating the installation. One is by a key system — magnification will result which will spoil the illusion of objects. Where Grandeur is projected at an angle of more than 15 degrees, it is necessary to use prisms to reduce the vertical distortion to a minimum, so as to reduce the elongation of objects, which is very objectionable when viewing the picture from the side seats. Problem of Illumination It is imperative that the Grandeur screen be well illuminated. At the present time there are no carbons manufactured to permit using over 170 amperes at the projector arc. Approximately 13 foot candles of illumination is required for satisfactory projection. Super-High-Intensity Lamps must be used to obtain the correct amount of illumination. With the Grandeur aperture 1.768 by .885, and by using the ordinary 41 in. planoconvex condenser combination, the illumination area is greatly reduced when the area of the aperture is circumscribed. It is obvious that if the same amount of light which passes through the aperture in an ordinary projector be spread over a screen area twice as large, the screen illumination would be only half as great. One obvious means of increasing the illumination is to employ condenser lenses of larger converging angle. About 25 per cent, more illumination can be obtained if the rear condenser lens (next to arc) has a cylindrical surface. Such a condenser will yield an elongated spot of light equal to that of the rectangle, without loss of light. It has been indicated that the relatively enormous picture on the screen may prove more satisfactory at a level of brightness lower than that to which we have been accustomed with the standard size picture. However, with the facts at hand concerning this matter, the requirements for illumination of the Grandeur picture are similar to those required for the standard size picture. an arrangement better suited, perhaps, to a garage where a renter engages space for a fixed period, say on a monthly basis. On this system each renter of garage-space is provided with a key which, if inserted in the lock panel and turned, brings his particular cradle and car down to the drive-away level. The same key operates the door-lock, which. however, can only be opened after the cradle has come to rest in its proper position. Other renters use the same drive-away and the same doors, but the key-system prevents anyone having access to any other cradle than his own. Swift — Simple — Safe ! The installation can also be worked by a simple push-button system and this is especially suited to a cinema’s needs. The push-buttons are located in a central office. A despatcher directs the customer to a vacant cradle and by pushing a button opens the door. An alternative way would be to have the customer drive close to the particular door showing a green light, whereupon the light from his car or a trackswitch operated by his car wheels causes the doors to open. When a patron returns for his car, the cashier pushes a button corresponding to the check number and the car is brought to the drive-away level and the doors are wide open by the time the customer has reached the door and is ready for his car. The third system of operation is by means of coins ; this is essentially the same as the push-button system, except that by depositing a coin the cradle is brought to the driveaway level and the door opened. This vertical garage system is likely to meet with ready acceptance by cinema architects and builders for its great simplicity ; convenience and economy of space and operating labour will make it a highly desirable annexe to any cinema. Projection of Wide Film