Rigid locking clamp used to permanently secure light stands, rails, or grip arms with no swivel or pivot capability.
Technical Details
Standard dimensions are based on tube diameters of 25mm, 32mm, and 48mm (Schedule 40). The jaws are made of hardened steel with a clamping force of 800-1200 Nm at tightening torques between 40-60 Nm. High-quality models from Manfrotto or Matthews use anodized aluminum with a wall thickness of 6mm. Mounting is done via M10 or M12 threads with a 28mm pin diameter (Baby Pin) or 16mm Junior Pin. Professional versions integrate safety cables with a 1500 kg breaking strength.
History & Development
In 1943, Mole-Richardson developed the first standardized Fixed Clamp for Hollywood studios to safely position heavy Tungsten Fresnel lights. Matthews Studio Equipment perfected the clamping principle in 1957 with the "C-Stand Grip Head," which is still produced unchanged today. While the transition to lighter HMI lights in the 1970s reduced requirements, it increased the demand for precise positioning without drift.
Practical Use in Film
On "Blade Runner 2049," cinematographer Roger Deakins secured hundreds of LED panels with Fixed Clamps on overhead rigs for uniform interior lighting. Steadicam operators require them for reproducible lighting setups during multiple takes of identical camera movements. In car rigs, they replace pivoting systems, as vibrations and G-forces would lead to slippage. Disadvantage: Every adjustment requires loosening and repositioning the entire clamp.
Comparison & Alternatives
Super Clamps (Cardellini Clamps) offer variable opening widths up to 55mm, but cost three times as much. Quick-release systems from Avenger reduce setup times by 60% but only achieve 70% of the holding force. Magnetic mounts replace Fixed Clamps during automotive shoots on vehicle bodies. Modern ball-head clamps combine fixed locking with unique 360° adjustment before securing.