Adjustable clamping device for securing lighting fixtures and equipment to horizontal bars and pipe supports.
Technical Details
Standard bar clamps support loads up to 25kg and feature a jaw opening of 25-48mm for common truss diameters. Heavy-duty variants can handle up to 75kg with a maximum opening of 60mm. The clamp body is made of hardened steel or aluminum alloy, and the jaws are rubber-coated to prevent damage. Baby bar clamps have 16mm spigots for smaller fixtures, while Junior versions have 28mm spigots for heavier units. Modern versions use quick-release levers instead of screw threads and achieve clamping forces of up to 2000N.
History & Development
The first documented bar clamp was developed in 1934 by Mole-Richardson for Hollywood productions to flexibly attach fixtures to the then-emerging overhead rigs. In Europe, the system became established from 1952 onwards when Bavaria Film Studios switched to American lighting technology. The breakthrough came in 1967 with Arri's self-releasing safety clamps, which open automatically under overload. Since the 1990s, quick-release mechanisms have dominated the market, and modern LED panels have led to ultra-light aluminum variants weighing under 200g.
Practical Use in Film
In "Blade Runner 2049" (2017), DoP Roger Deakins used over 400 bar clamps daily for the complex overhead lighting of the city scenes. Typical workflow: Fixtures are prepared on the ground, mounted to trusses via bar clamps, and hydraulically moved into position. The advantage is 360-degree rotation and quick repositioning without disassembly. The disadvantage: Limitation to the existing truss grid; vibrations from insufficient fixation can cause image blur with long focal lengths.
Comparison & Alternatives
Unlike rigid fixture hooks, bar clamps allow tilt angles up to 90 degrees. Magnetic mounts are faster but can only be used on ferromagnetic surfaces and are less load-bearing (maximum 15kg). Suction cup systems work on smooth surfaces but only achieve a load capacity of 8kg. For exterior shots without truss infrastructure, traditional tripods remain the alternative, but they require significantly more floor space and setup time.