FLASH-LIGHT PHOTOGRAPHY.
powdered magnesium, or magnesium dust, be forcibly blown through a flame a rapid combustion of the metal takes place, and the result is a brilliant flash of light. other substances, in themselves non-combustible, may be made to ignite in the same way. Indeed, the flash lamp of to-day was probably suggested by the old-fashioned plan of producing stage lightning by blowing powdered lyco podium through a flame. The light produced by the mag nesium flash is sufficiently actinic to permit of a photograph being taken with it, and, indeed, if a little trouble be taken, most excellent results may be obtained. The exposure being practically instantaneous, the sitters can be taken in an ordinary room, and whilst engaged in ordinary occupations in natural attitudes without fear of movement.
A great deal of ingenuity has been expended in the con struction of " flash-lamps," as the apparatus used in pro ducing the light is called, and the reader will find in the shop of any dealer in photographic materials quite a bewildering assortment from which to choose. It is not my intention here to describe in detail the merits or demerits of the different forms of lamps. Some, no doubt, are more efficient than others, hut a suitable lamp should be easily procurable for about 4s., or even less. The general principle of construction is the same in all lamps, that shown in fig. 26 being designed by Mr. England : A is a metal chamber upon the top of which a wad of felt, which has been saturated with methylated spirit, is placed ; B is a tube in which the magnesium powder is placed, about 10 gr. being sufficient. The tube B comes out at C, and is there connected, by means of a piece of india-rubber tube, with a collapsible india-rubber ball. Upon smartly squeezing the ball the air-pressure drives the magnesium powder through the flame, producing an elongated flash of great brilliancy.
It is difficult to get the best effects of lighting with only one lamp, and much better results will be obtained if two, or even three, are employed. It will, of course, be neces
sary to so arrange matters that the three flashes shall be simultaneous ; but this is by no means difficult to do. Sup posing three lamps are to be employed, a prong-shaped piece of tube must be procured of the shape shown in fig. 27. The lamps are connected by lengths of tubing to 1, 2, and 3, No. 4 being connected by means of another piece of tubing to the pneumatic ball arrangement, or, better still, when several lamps have to be fired simultaneously, to a pair of ordinary bellows.
The general directions given in the preceding chapter upon indoor portraiture apply equally when the exposure is made by flash-light, and, therefore, it will not be necessary to repeat them again here. The most important matter to be attended to is the arrangement of the lamps. The object to be aimed at is to get a good soft lighting, which will bring out the feature; in well-modelled relief. This, as I previously mentioned,. it is difficult to do with one lamp, and the most suitable disposition of the lamps and sitter may best be shown by the aid of a diagr, am. In fig. 29, A represents the sitter, or sitters, B being the camera, and 0, D, E the three lamps. These must always be either behind the camera, or at any rate screencd from the lens, and well out of its field, or hopeless fogging of the plate will result. If the lamps are placed close together a hard un pleasant lighting with heavy shadows is likely to result, but by placing them in the position shown in the diagram an artistic effect should be produced. The great advantage of this system of lighting over ordinary daylight is that the sitters may be placed in any desired part of the room, and one is not hampered with any such considerations as getting the most suitable lighting from the window. Very natural and pleasing pictures may be taken in this way, but much will, of course, depend upon the artistic ability of the operator.