Facilities of Fastening and Suspension of Luminariers
By Michael Lvov

One of the problems when filming organization in film studio is distribution and fastening of luminariers. Relatively often for this purpose different tripods are used. However this method is appropriate in outdoors shooting, but when operating in studio it is difficult to call it effective. Really, tripods take to much space in already small filming studio (doesn't matter of what size the studio is, it is always small by some reasons), where there are lots of other equipment, such as cameras, monitors, pedestals, cranes, furniture, etc. Besides, the more powerful and as well massive the luminarier is, the bigger tripod it needs. And in correlation of facility itself with the area taken by tripod, which it is fixed on is obviously not an advantage of equipment fixing on the tripod. And the bigger the weight of the luminarier and height of its setting are, the bigger must be opening of the tripod and the bigger footprint it takes. And now imagine that there are ten of different luminariers in the studio. Moving between them starts to remain slalom. Besides operation with big in size and weight projectors and lamps provides difficulties as their lifting and sinking by hand requires some physical strength.

Shooting pavillion equipped with different suspension facilities

Problems are not limited only to what was said earlier. The main, from my point of view, from them is varying of light picture of studio, for what it is necessary to change situation of big number of luminariers. In case of tripod using that means carrying of all equipment by hand, what is not only uncomfortable, but also slow and difficult physically. Additionally it can end with burns as facilities with incandescent lamps warm significantly while operating and usually there is no time to wait while they cool down. And there appear difficulties with power cables, which are necessary to be connected to other sockets and they usually get become tangled.

One of grips for devise fixation

Spring pantograph in upper (in the left) and partly lowered positions

All that can be avoided if using for fastening and suspension of luminariers and other studio equipment contemporary facilities, such as clamps, claws, pegs, pantographs, telescopic and other brackets, pan-and-tilt heads, guides, etc. Let's take a look at each one of these facilities more specifically.

The simplest and the most often used facility, with no doubts are clamps, claws and pegs. I don't think that it is necessary to tell about the construction of these facilities. It is enough to say that clamp, claw and peg are relatively similar. All of them have the same hard element of determined shape (in case of clamp it is C-shaped cramp of determined profile of brand, double-T or channel). For fastening the spring or any elastic element is used. It is necessary to mention that these facilities allow fastening of luminariers in almost any appropriate load-carrying structure like table, shelf, girder, guide, etc. When outdoor shooting in the set with tripod these facilities are indispensable. Simplicity of the construction guarantees reliability and long service life of devices and also simplicity of working with them.

Pantograph represents the system, that consists of load-carrying structure of parallelogram type (something like accordion), setting units and power element (spiral springs, ropes, electric drive). Besides the construction includes electric wiring with cutoff points for connection of equipment settled on the pantograph and units of their control. Elements of load-carrying structure are hingedly connected between themselves what allows changing its length in relatively wide limits, providing opportunities of regulation of luminariers height.

Dolly (cart) for pantograph-to rail connection

Pantograph's drum with spiral spring

Motorized pantograph drive

Setting units that pantographs are equipped with serve for suspension of equipment to them and also for setting of pantographs themselves on girders or guides. Sliding fastening when pantograph is suspended on the trolley capable of moving along guides is provided. Moving is simplified by reel presence. For prevention of reel sliding from guides trolleys are equipped with stops.

Spiral springs serve for weight compensation of luminarier. Their amount is usually equal to two or four. Depending on the weight of equipment fixed on the pantograph some springs can be disconnected. For that are provided pieces of steel rope ended with carbine are attached to free ends of springs. By right choosing of amount of active springs lighter receives an opportunity to change the height of facility suspension with small afford. Cargo carrying capacity of pantograph spring can achieve few tens kilograms (usually up to 40 kg).

Rope pantographs as it can be seen from their name are equipped with steel ropes as the power element. For changing of the rope length and, accordingly, of the entire pantograph, small winches are used, which are hand controlled with the help of special telescopic bars with hook on the end. On the pantograph itself there is a wheel connected with winch. In that wheel the bar is set in with the help of which the winch can be rotated. In spite of that rope pantographs are less comfortable in work as you have to rotate bar constantly to change facility height, they are unique by big cargo carrying capacity (usually on 10...15 kg more than an spring ones), don't require selection of spring quantity, and provide more reliable fixation of chosen equipment on chosen height.

The top of the pantograph family is motorized facilities. It is not difficult to guess that for lifting and sinking of useful loading server electric drive. To operate with such facilities is simpler and easier due to some reasons. First, they absolutely exclude applying of physical power, second, accuracy of positioning of these pantographs is much higher than at others. Due to the fact that electric motor is sensible to overloading, motorized pantographs are equipped with sensor of maximum weight excess. But that doesn't mean that in case of excess of maximum loading value pantograph won't work at all. The scheme of electric drive usually is done so that in case of overloading pantograph would work only on sinking. For shutting down of electric drive power in the side upper and bottoms points are also fixed according sensors. When taking off of power from electric motor the brake turns on automatically, which prevents spontaneous movement of luminarier. Motorized pantographs have some other advantages. They carry load bigger than the rope ones (up to 60...70 kg). Electric drive control scheme provides smooth start, what excludes any shacking of luminariers, to which incandescent lamps are sensitive. But the most important that distinguishes motorized pantographs is an opportunity of their integration with systems of automatical lightning of all film studios. For that purpose pantographs are equipped with corresponding interface.

Telescope scheme

Telescopic bracket represents the facility with adjustable tubular bearing element (with one, two or more sections), which moving is done with the help of electric drive with rope. Electric drive is equipped with limiting sensors and automatical brake. The fastening type provides two variants: hard and for moving along guides. In the first case the bracket fixes firmly to the ceiling and the movement of luminarier is possible only vertically in the limits of telescopic tube start. In second case the bracket is equipped with trolley for moving along guides or circular or other section. Trolley can be with electric drive or without (hand moving). Usually trolley for hand moving is used when the bracket slides along single guide. If the facility is hanging on the girder (on to parallel guides) the braking trolley is used. For packing of power cable serves special basket situated on the lower end of the telescopic bar, directly above the setting unit of facility. The length of bar start achieves 10 m.

All named earlier facilities can carry only one luminarier and allow moving it along two coordinates maximum.

In cases when appears the necessity of fastening in one facility of few equipment units at the same time or moving of the facility along three coordinates other kinds of brackets are used: motorized and automated elevators. The functional differences between them are not significant, however they differ from each other constructively. First of all there is some sense to view the similarities of these facilities. Both can carry up to few facilities at the same time for what bar-guide is assigned. Limits are the maximum weight if each one of them. First limit is obvious and doesn't need explications. Second is provoked by the limit of guide strength: dotty load can't be more than permitted one to avoid its deformation and even destruction. Elevators provide moving along three coordinates: vertically and by perpendicular directions in horizontal plane. Vertical moving is done by the length change of suspended ropes by the electric drive. Horizontal moving of entire system along one of the guides on which the elevator's trolley is situated and by another can be moved each one of the fixed on it facilities for that purpose special trolley with reels is provided.

Motorized climber scheme

Motorized elevators have articulated construction element, which prevents system fluctuations while moving and additionally serves as guide for power and signal cables (as on the elevator can also be fixed, for example, monitor). Besides these facilities are equipped with control ports, as they can be a part of automated light control system.

Automated elevators represent more perfect facilities, suspended on two powerful steel ropes and capable of carrying much bigger loading than motorized ones. Maximum loading on these facilities can be more that 200 kg, and effective rope length achieves 13...14 m. So automated elevators are especially effective in large film studios.

Pan/tilt head with lighting device

Changing guide-bars allow enlarging the diapason of luminariers moving along one of the coordinates in horizontal plane and also to increase their amount on one elevator. Naturally, automatical elevators are equipped with all necessary cutoff points for power supply and receiving/transfer of signal.

It is impossible to stop shortly on such facilities as panorama heads. They serve for position changing of fixed luminarier. These heads allow producing vertical and horizontal panning for what two electromechanical drives of the head serve. Control of the head itself usually is wire remote. Panning heads are indispensable in cases when it is necessary to change light picture directly during filming.

Climbers installed in the studio

This very short survey would be incomplete without the information about elements that are assigned for carrying of all of the facilities that were named here. It is about single guides (railing) and girders. They are produced in the shape of tubes or complicated rectangular profiles made from aluminum alloy. Some guides are equipped with special current-carrying elements (trolleys), what relieve from the necessity to reach out for bracket elements and settings of power cable. Power of suspended facilities is done through sliding current collectors (brushes).

It is obvious that application of mentioned facilities significantly simplifies works in studio, makes them more effective and also allows getting clear so necessary film studio square. Naturally, in small article it is difficult to give full information about these and other facilities of fastening of luminariers and other television equipment. We hope, that reader anyway received main information necessary for successful and effective operation in the field of television and broadcasting.

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