In projection the speed can be adjusted. The ten thousand pictures per second may be decelerated to sixteen per second to allow the movement to be followed, and although the rifle bullet may appear to crawl through the air, the movement is perfectly correct. Similarly the very slow motions must be accelerated to sixteen pictures per second to obtain evident animation. These two extreme phases of cinematographic investigation are described at length in another part of this volume, but are mentioned here merely to show that the photographing speed is a somewhat elastic factor, to be adapted to circumstances in order to produce passably natural effects.
For everyday work, however, a speed of sixteen pictures per second is sufficient and represents the generally practised velocity. Possibly in the near future the speed will be accelerated to twenty, twenty-two, or twenty-four pictures per second, as the present speed is generally admitted to be too slow. The eyes of the regular picture palace patrons have become trained, as it were, with the result that there is an appreciable strain of the eyes, while the disjointed character of the movements on the screen may be detected. But when the taking and projecting speed is accelerated by 50 per cent. the picture stands steadier upon the screen, the movements are more natural, and there is an entire absence of that automaton effect which is so characteristic of most pictures taken under prevailing conditions. These considerations do not affect photo-plays produced in the studio so materially, because there the actions of the players can be slowed down to suit the conditions.
One of the leading manufacturers is earnestly considering the advisability of accelerating the taking and projecting speeds up to about twenty pictures per second, and private investigations and experiments have certainly demonstrated the value of such an improvement. Unfortunately two difficulties prevent its immediate realisation. An increase of only four pictures per second represents an increase of 25 per cent. in the consumption of the film, and therefore in its cost. The other difficulty is more serious. Existing apparatus, both cameras and projectors, are geared to eight pictures per turn of the handle. This involves two complete revolutions per second. Consequently the gearing of the mechanism would have to be altered, and this is a more troublesome question than appears at first sight. Some time may elapse before a forward step is taken in this direction. In matters of this character the cinematograph industry is notoriously conservative, although the moment one firm courageously adopts an accelerated speed, the higher quality of the resulting pictures will force the others to follow the example.
As a matter of fact the decision to adopt sixteen pictures per second was taken somewhat haphazardly without any scientific investigation. When it became standardised, film was expensive. Accordingly, efforts were made to secure the requisite effect with the minimum expenditure of film. Machines were built to coincide with these requirements, and the original designs have been followed slavishly in their broad outlines ever since.
CHAPTER III
THE MOVING-PICTURE CAMERA AND ITS MECHANISM
The cinematograph camera differs entirely from the instruments used in other branches of photography. While the advanced worker and the prosperous picture-play producer employ costly and elaborate machines, the amateur, or the independent worker, in the particular field which he has selected for his operations, can get equally good results with an apparatus only a fifteenth or even a twentieth part as expensive. The range of operation with the cheaper instrument may be limited, and it may be deficient in those many little refinements which are characteristic of the professional appliance, and may lack silver-plated finish and highly-polished woodwork or morocco leather covering. But the camera itself is more important than these.