Kinematograph Photography.—This involves similar lighting conditions to those necessary in ordinary photography. Excepting in the case of stage scenes and " make-ups," the operator of the kinematograph camera does not know many moments in advance what is going to happen next. A crowd of people may, perchance, un consciously group themselves into a most desir able arrangement, but the chances are they will not. An elevated position should be chosen, so that possible obstructions, such as people passing close to the lens, and, therefore, out of focus, are avoided. The direction of the light, especi ally at noon, should be oblique and coming from the back of the operator, either from his right or left ; direct front lighting should be avoided. Ideal illumination occurs when the sky is thinly overcast, with plenty of light sifting through the clouds. Critical definition, a full range of tone values, and exact speed with even motion, are the three chief points to be aimed at. The first point relates to choice and management of the lens and the adjustment of the shutter aperture ; the second relates to the light and afterwards to proper development ; and the third to the correct operating of the mechanism. The handle must be turned at the rate of two revolutions per second, and its speed must be regular through out the operation, irrespective of all else.
" Make-ups " and stage subjects afford oppor tunities of arrangements not possible with topical or street scenes. The questions of lighting and optical conditions remain the same. Stages on which motion-picture plots are executed are generally on the tops of houses, so that as the sun alters its position, there are no shadows of surrounding buildings cast upon the scene ; but the house-top studio is not to be preferred to a good open space on the ground level. The pro fessional's stage is built on the revolving principle, so that the direction of the lighting can be kept constant throughout the day. The amateur is not likely to want to take more than two or three subjects in one day, and these he can arrange for when the lighting is at its best.
When the camera has been set up on a rock-steady support, the field covered by the lens should be marked out on the floor of the stage by means of white tape or chalk lines, as an indication to the actors. The time limit for the actions in each section is arrived at by rehearsing the play, whilst the operator turns the handle of his machine at the recognised speed ; the camera need not be loaded, providing it is fitted with a speed-indicator. It is the work of the stage manager to watch the acting and to decide upon the question of elimination. All superfluous action is cut out, not only to reduce expense, but to crystallise the plot. No action is introduced that can be assumed to happen, and only such natural motions are allowed as will render the subject intelligible to the average mind.
Trick and Make-up Subjects.—Motion-picture photography lends itself to trickery and make believe more than any other branch of the picture making art. In subjects where human beings are represented as passing through great peril, the stop-camera method is resorted to. Thus, an
actual person acts the part up to the safe stage ; the camera is then stopped, and a dummy sub stitute provided, made up to represent the original. In like manner, when inanimate objects are made to move without apparent human control—such, for instance, as a knife cutting by itself a loaf of bread ; cups and saucers collecting themselves into a heap ; and so on—the photo grapher takes one or two pictures, stops, the articles are moved to the second position in their progress of movement, the camera again operated for the space of one or two pictures and again stopped, the articles moved to their third position, and so on through the entire series of pictures. The process naturally takes a long time to accom plish, but the results are often well worth the trouble expended. Some cameras are fitted with means whereby the operator may ensure expos ing only one picture space at a time, and an assistant generally carries out the work of alter ing the positions of the objects after each expo sure. If a camera has its shutter aperture so adjusted that sufficient exposure is obtained whilst operating at less than the normal speed of sixteen exposures per second, a subject moving normally will appear to be moving swiftly when projected upon the screen ; the opposite holds good when the camera is operated abnormally quick.
Stationary subjects, such as a man's face, may be represented as increasing in magnitude by causing the camera to travel towards the subject during operation. Likewise, diminution of ob jects may be produced by taking the camera away from the subject during operation. This diminishing and growing magnitude effect inci dentally creates the illusion of an approaching or receding subject. Hence, a train represented on the screen as approaching, appears by its ever increasing size, to rush almost off the sheet into the auditorium.
To give the effect of a balloon rising or falling, or a flying machine travelling in space, rollable backgrounds, on which are depicted distant land and clouds, are placed behind the scene and operated. The rollers on which such back grounds are wound are fitted to supports capable of universal movement in one plane. If a balloon or any other object is to be represented as ascending, the background is wound from top roller to bottom, passing downwards, or in an opposite direction to that in which the balloon is supposed to be moving. If a flying machine is represented as travelling from left to right, the background is moved in panoramic order from right to left.
Many other effects are produced by what is known as composite printing, in which process masking is resorted to and the print made by exposure in contact with two, three or more separate negative films in succession, according to the complexity of the subject to be produced.
Dissolving effects are produced as described under the heading " Dissolving-views." Under the heading " Aerial Screen " is explained one method of producing " ghost effects " in trine. matography.