Lighting Suspension Systems
A flexible lighting suspension system is one which allows for easy and rapid positioning of a luminaire to within 0.6 m (2 ft) of any position in the studio. This enables a short turnround time to be achieved and allows the lighting director to position his lamps in a reasonably precise way. Flexibility usually requires an expensive suspension system. The most elaborate facilities (lighting bars on motorised hoists, and motorised telescopic methods) are not included here, as their high cost is not usually justified for the small television studio.
Pipe grid
This system has the advantages of being relatively cheap, and easy to modify. All the piping and clamps are standard construction items. The grid consists of a horizontal framework made from tubular piping of 48 mm diameter. The spacing between the grid members should ideally be 1.2 m (4 ft). The height of the grid should be at least 3 m (10 ft) —remember that any suspended lamp will be hanging below this. The preferred grid height is 3.6 m (12 ft). It offers a good lamp height, and it is reasonably easy to move equipment around. If the grid is above 4.2 m (14 ft) lamp-handling is more difficult.
Extra flexibility can be achieved by including a number of drop-arms or lightweight pantographs. The pantographs are more complex and expensive, but allow rapid adjustment of the luminaire height.
Heavy track suspension
This provides good flexibility. The basic arrangement consists of a number of heavy-duty tracks from which the luminaires are suspended on pantographs. A minimum studio height of 4.8 m (16 ft) is required. Each track is fitted with four luminaires which can be moved along it. The system is extremely flexible if the luminaires are dual source, i.e. spotlight/softlight. The spacing of the tracks must be such that two luminaires on adjacent tracks can pass each other. A track spacing of 1.2 m (4 ft) is a good compromise. Power is extended to the luminaires by a catenary system. The method for adding extra luminaires (e.g. for effects) depends on the type of track used. To allow for lighting from above a cyclorama, a peripheral lighting rail is added.
A development of this system is shown opposite (bottom) where the luminaires, on pantographs, slide on heavy-duty transverse tracks. The transverse tracks also slide in longitudinal tracks. This results in a readily adaptable lighting rig.
If the studio ceiling is not strong enough to take the weight of such suspension systems plus the luminaires, additional supporting steelwork may be built up from the studio floor in the form of tubular pole ‘ladders’.
1. Lighting grid. Cheap, easy to install and modify if requirements change. Most suitable for low ceiling heights.
2. Drop arm used to lower the lamp height by a fixed amount. Its length may be pre-adjusted.
3. Telescopic drop arm of adjustable length allows lamp height to be altered readily over a couple of feet.
4. Pantographs are adjustable over a wider range.
Ceiling power tracks
Heavy duty suspension tracks may span the ceiling, e.g. six tracks with four luminaires run on each track, powered from catenary tracks. They should be supplemented by a peripheral track.
Adjustable lighting grid/lighting track
In this system part of the lighting grid is mounted on rollers which allow it to move in one direction. This produces a grid system which can be easily changed to meet each production’s requirements. Ideally the luminaires should be suspended on trolley-mounted pantographs which run on the shorter moveable tracks. Again a peripheral track should be included, and consideration given to permanent cyclorama lighting from separate drop arms/pantographs.
