BS 5550-3.9.1 is a British standard and a part of the BS 5550 series that discusses the specification of projector spools for 35 mm film spools of 610 m capacity (38 cm size) for release prints for cinematography. Cinematography sets and supports the overall look and mood of a film's visual narrative.
BS 5550-3.9.1 prescribes the requirements for spools with metal flanges, to take standard 2,000 ft. 35-mm. cinematograph release prints and accommodate the maximum permissible length of 2,050 ft. of film. BS 5550-3.9.1 specifies dimensions, essential points of construction, the accuracy of assembly, the materials to be used, and the finish required.
BS 5550-3.9.1 also provides for the need to earth the spool and film to permit the discharge of any static electricity that may accumulate during use.
BS 5550-3.9.1 on projector spools applies to:
Cinematography sets and supports the overall look and mood of a film's visual narrative. The tower is designed with four spools, two on each side, each with its motor. This allows the whole spool to be immediately rewound after a showing, the extra two spools on the other side allow for a film to be shown while another is being rewound or even made up directly onto the tower.
BS 5550-3.9.1 provides you with the guidance on the finish which includes: The spool is free from sharp edges, the finish protects the spool adequately against corrosion under normal conditions of use, the finish does not prevent the discharge of static electricity from the film to the spindle of the projector or winding machine.
Overall, BS 5550-3.9.1 exemplifies the required dimensions and specifications that help you in cinematography.