The international photographer (Jan-Dec 1934)

July, 1934 The INTERNATIONAL PHOTOGRAPHE / wenty-three the sides of the reflector, than by facing the lens. rectilinear spread in a horizontal or vertical direction. Also, the original lamps were such that they had to be The Klieglight is perfectly balanced and adjustablj burned with the base down, and necessitated an additional mounted on swivel bearings, in a yoke, and swings easily hole in the top of the reflector in order to get the lamp in in any direction and sets on a telescopic pedestal stand and out of the socket. This was objectionable and was fitted with ball-bearing rubber-tired casters, permitting it overcome by a decided change in the lamp itself. After experimenting, the General Electric Company developed the bipost base-up-burning biplane filament lamps for use with Klieglights — and they are now available in 1 24 bulb, 1000 and 1 500-watt sizes, and T-30 bulb, 2000watt size. (200 Hour or 25 Hour life — the latter being recommended for color photography ) . The filament center of all three lamps is the same. In these new lamps the filament is placed far down in the tip of the bulb, which procures a two-fold advantage. to roll easily over the floor. It is also provided with an auxiliary support so that the projector can be set on the base close to the floor when required. A 25-ampere snap switch, mounted in the hinged back casing of the lamp housing controls the main line. General Advantages It accomplishes results in a simple, direct manner, provides uniform high intensity illumination, and considerably lowers lighting cost. It gives over three times the light for the same wattage input than any conventional ( 1 ) minimize the amount of glass inside of the reflecting type Qf unjt procJuced up to the present time, and utilizes system; (2) all the blackening of the bulb takes place near the top of its neck which is outside of the reflector. This arrangement permits the maintenance of the initial efficiency for a long period of time. The lamp holder is removable, and specially devised to securely retain the lamp in a fixed prefocused position, at an angle of 45° — rotary adjustments being provided for properly setting the lamp filament in respect to the lens, to procure a maximum output and even distribution of light. The lamps are designed to operate anywhere within a 45 degree tilt either side of the vertical, and by mounting it offset at a 45 degree tilt from the vertical in the lamp housing, it permits a full 90 degrees down tilt of the Klieglight unit, so essential for motion picture use. The lamp housing is thoroughly air cooled by an improved direct-draft system of ventilation — with vent openings top and bottom, which allow a full and continuous passage of air through the hood — thus prolongs the life of the lamp, and insures cool, economical operation. This louvre ventilation system prevents light leakage without interference with the air circulation. The lens system is another new idea which was incorporated in this model. A double lens arrangement on a movable carrier in the cylindrical front housing, permits both beam adjustment and beam intensity variations. By varying the position of the two lenses in respect to each other both the intensity and the spread of the beam can be varied — without the use of a dimmer. The operation is independent of the framing shutters — which may be changed or remain set, as desired, while the lenses are varied. By using lenses of different focal lengths — different degrees of maximum beam-spreads can be obtained. The units are furnished equipped with lenses to suit individual requirements, of the correct focal length to give the maximum spread specified, with maximum lighting efficiency. Both square and round (iris) adjustable shutters are a part of this unit. They are located between the lamp and the pick up lens in a focal position directly related to the lens system and its beam control. The iris shutter regulates the circular diameter of the light beam, and a projecting handle controls its operation, opens or closes the shutter from black out to a pin point, and to full sized beam. The framing shutters are for shaping square, rectangular, and other angular formations of the light beam, any size desired — and consist of two vertical and two horizontal freely-moving independently adjustable blades with protruding handles, permitting any desired arrangement. Slide grooves are provided on front of housing, to receive media frames for color lighting effects ; or a special spread lens can be placed in the slide grooves to procure a wider horizontal or vertical spread of light, if necessary — these are now available in practically any degree spread practical} the entire light output of the lamp under all operating conditions — that is the efficiency or total output remains the same whether the light beam is spread or concentrated. Beam control is one of its most interesting and valuable features — that make the unit especially well suited for studio lighting. By means of the adjustable lens system, in conjunction with the adjustable shutters, both the size of the held illuminated and the intensity can be varied in several ways. For example, by simply changing the shutter opening and leaving the lenses set, the area illuminated can be altered while maintaining the same degree of intensity as before ; or by moving the lens the spread can be increased or decreased, and by adjusting both the lens system and the shutters, the lighting can be intensified or diminished without increasing or decreasing the size area illuminated — or vice versa — including a number of intermediate adjustments between the two extremes. Thus is provided means for obtaining practically any size or intensity of spot or flood within the wide operating range of the unit — without the necessity of using a dimmer, and as it has no spill light it also eliminates the use of gobo-lights shields, framing cardboards and the like. The light can be projected through doorways, without lighting the sills and adjacent walls ; or sun shadows, can be cast on the walls in any direction required. A great amount of light can be directed on any particular section, or article of a set without spill over. Thus besides providing for general illumination, it also provides complete self-contained forming control — quick acting and certain. These new Klieglights are adaptable to a great variety of applications — and can be used for either spot or floodlighting, indoors or outdoors, for long or short range work. In addition to the many applications in motion picture studios, already mentioned, they are also well adapted for color lighting of studio sets — now in experimental stages, and here, too, the expense of larger size color mediums is avoided. In the theatre they are ideal for use as proscenium lights; balcony front lights; ceiling floods for illuminating the front of stage and orchestra pit and for general spotlights on the stage. They may aso be used for indoor or outdoor floodlighting of buildings, fountains, arenas, church lighting of altars, etc cetera. Hotels have used them both as spot and floods, paiticularly for the lighting of runways for fashion shows. In fact, they may be used wherever a sharp cut off light, of high intensity, without any spill is required. The distinctive advantages of these new Klieglights have been quickly recognized, and their use promptly effected in many commercial projects as well as theatres" and motion picture studios. Mr. Powell, supervising engineer of the General Electric Company stated he considered the new Klieglight to be one of the greatest outstanding developments in the lighting units of the last few years. desired, and may be had either with a circular spread or Please mention The International Photographer when corresponding with advertisers.