Overview
ISO 3047:1982 defines the dimensions and characteristics of the daylight-loading spool for 35 mm motion-picture cameras with a nominal capacity of 30 m (100 ft). Published by ISO Technical Committee TC 36 (Cinematography), this standard ensures mechanical compatibility, interchangeability and reliable operation of general‑purpose spools used in photographic and motion‑picture equipment.
Key topics and technical requirements
- Scope: Spool geometry and dimensional tolerances for 35 mm, 30 m (100 ft) daylight-loading spools. The standard notes substantial agreement with corresponding microfilm spools (see ISO 1116).
- Core and flange geometry: Defines a reference plane of rotation using a 15.0 mm (0.59 in) diameter support centred on the spindle hole axis; specifies how flange thickness (dimension J) and eccentricity are measured.
- Slot (dimension F): Slot sides adjacent to each flange must be straight, parallel and 0.7–1.5 mm (0.03–0.06 in) apart; slot sides must extend a minimum of 6.0 mm (0.24 in) from each flange toward the center.
- Spindle and drive holes: Permitted hole shapes include square and round types; when square holes are used in both flanges, alignment must allow an 8.03 mm (0.316 in) square test bar to pass through. Drive holes or slots are optional; offset drive holes are permitted on circles defined by radii U and V (as illustrated in the standard).
- Runout and eccentricity: Core eccentricity relative to spindle axis must not exceed a total radius variation of 1.0 mm (0.04 in). Runout and tolerancing follow ISO 1101 principles.
- Thickness and overall limits: Maximum overall effective thickness (including flange characteristics and eccentricity allowances) is established - the standard gives a maximum overall figure of 38.90 mm (1.530 in). Rivet heads or fastening devices must lie outside the defined K diameter area.
- Optical/finish note: Flanges shall be opaque with low reflectance.
Applications and users
- Camera and accessory manufacturers designing daylight-loading mechanisms for 35 mm motion‑picture cameras.
- Spare‑part suppliers and molders producing compatible spools for interchangeability.
- Film laboratories, archivists and restoration facilities needing standardized spools for handling and transfer.
- Manufacturers aiming to produce a single spool type for both motion‑picture and microfilm applications (see annex guidance).
Related standards
- ISO 1116 - Microcopying: spools and reels (related dimensions for microfilm spools)
- ISO 1101 - Geometrical tolerancing: form, orientation, location and runout (referenced for runout measurements)
Keywords: ISO 3047, 35 mm spool dimensions, daylight loading spool, cinematography standard, spool specifications, 30 m 100 ft spool.
Open preview (PDF)Cinematography — Spool, daylight loading type, for 35 mm motion-picture cameras (capacity 30 m - 100 ft) — Dimensions