Overview
ISO 1793:2005 - "Cinematography - Reels for 16 mm motion‑picture projectors (up to and including 610 m capacity: 38 cm size) - Dimensions" - specifies the required dimensions and characteristics for 16 mm film projection reels. The second edition (2005) expands reel capacity ranges (now covering 60 m to 610 m) and updates dimensional tolerances and mechanical requirements to ensure interchangeability and reliable operation in projectors, rewinds and containers.
Key topics and technical requirements
- Scope: Dimensional and characteristic requirements for 16 mm projection reels with capacities up to 610 m (2 000 ft).
- Dimensional control: Detailed figures and tables define nominal values and tolerances for hub and flange diameters, reel thickness and spacing to ensure consistent winding and transport.
- Flange clearance and film channel:
- Distance between flanges at spindle holes and at hub is specified to provide correct lateral clearance for film (designed for max film width 16 mm).
- The outer surface of the flanges must be flat out to at least 31.75 mm (1.250 in) diameter to control film winding behavior.
- Spindle hole and keyway:
- Reels may use a square spindle hole with corner keyways or a single round spindle hole. If square holes are used, an 8.02 mm (0.316 in) test bar must pass completely through the reel to confirm alignment.
- Keyway openings are dimensioned to fit alternate spindles used in some laboratories.
- Mechanical limits:
- Fastening elements (rivets) must not protrude more than 0.8 mm (0.03 in) beyond flange surfaces.
- Permissible flange and hub eccentricity and lateral runout limits are defined to prevent wobble and film jog during projection.
- Flange rigidity test:
- A standardized load test (2.2 N plus additional 4.4 N) measures flange deflection; additional deflection caused by the higher load must be less than 0.89 mm (0.035 in) to meet strength requirements.
- Film tension guidance: The standard recommends keeping film tension low and maximizing the hub-to-flange diameter ratio (B/A) to reduce perforation risk and improve winding consistency.
Applications and users
ISO 1793:2005 is used by:
- Reel manufacturers designing or validating 16 mm film projection reels
- Equipment manufacturers (projectors, rewinds, storage containers) ensuring compatibility
- Film laboratories and archives that handle, store and transport 16 mm film
- Technical procurement and quality assurance teams specifying reel dimensions and mechanical performance
Adopting ISO 1793 helps ensure reliable film handling, reduced wear/damage, and cross‑compatibility between reels and projection hardware.
Related standards
- ISO 1019:1982 - 16 mm camera spools (daylight loading) - dimensions
- ISO 3647:1976 - Spindles for 16 mm camera spools and projector reels - dimensions
- SMPTE 235-1998 - 16 mm projection reels (broader capacity ranges)
Keywords: ISO 1793:2005, 16 mm film, projection reels, reel dimensions, flange rigidity, spindle hole, keyway, lateral runout, reel capacity.