ISO 491-2002 PDF

Full title and description

Cinematography — 35 mm motion-picture film and magnetic film — Cutting and perforating dimensions. This International Standard specifies the cutting and perforating dimensional requirements and the types of perforations used for 35 mm unexposed motion‑picture film and 35 mm magnetic film, intended to ensure interchangeability and correct sprocket engagement in cameras, printers and projectors.

Abstract

ISO 491:2002 defines the nominal dimensions and tolerances for 35 mm film width, perforation pitch and position, and the geometries of common perforation types (for example Type P, Type N and Type DH). It specifies measurement conditions (reference temperature and relative humidity), pitch definitions (long and short pitch), and includes annex material on normative dimensions and informational guidance on dimensional stability and low‑shrinkage film.

General information

• Status: Published.
• Publication date: 2002‑08 (August 2002).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 37.060.20 (Motion picture films. Cartridges).
• Edition / version: Edition 6 (ISO 491:2002).
• Number of pages: 7 pages (official ISO publication length).

(General information above is taken from ISO's bibliographic record for ISO 491:2002.)

Scope

Applies to unexposed 35 mm motion‑picture film and 35 mm magnetic film: specifies cutting and perforating dimensions at the time of manufacture, defines acceptable tolerances, and identifies the standard perforation types used for camera, intermediate and print stocks. Measurement conditions used to define the dimensions are specified (reference atmosphere). The standard is intended to support manufacturing, processing and equipment compatibility for 35 mm film formats.

Key topics and requirements

• Normative nominal dimensions and tolerances for overall film width and perforation geometry (examples in the standard include nominal overall width ≈ 34.975 mm with tight tolerances and perforation pitch values for long/short pitch).
• Definition and drawings of perforation types (Type P, Type N, Type DH) including hole shape, radii and position relative to the film edge.
• Pitch definitions: long pitch (B) and short pitch (B'), with specified tolerances and guidance on when each pitch is used (camera, printer or print stocks).
• Measurement conditions: dimensions apply at reference atmosphere (23 ± 1) °C and (50 ± 5) % RH unless otherwise stated.
• Requirements and guidance related to dimensional stability and low‑shrinkage film (informative material on shrinkage/swelling effects and how they influence pitch/printing).
• Normative tables and an inch‑equivalent annex to support international manufacturing and equipment alignment.

Typical use and users

Used by film stock manufacturers, perforating and slitting equipment suppliers, film laboratories, post‑production houses, camera and projector developers, archival and preservation organizations, and standards/quality engineers involved in the manufacture, processing and handling of 35 mm motion‑picture and magnetic film.

Related standards

Commonly referenced and related ISO documents include ISO 18906 (photographic films — safety/specification), ISO 554 (standard atmospheres for conditioning/testing), and other cinematography standards covering image areas and print dimensions (for example ISO 2906, ISO 2907, ISO 2939 and related ISO/TC 36 publications). The British adoption is published as BS ISO 491:2002.

Keywords

35 mm film, motion‑picture film, magnetic film, perforation, sprocket, pitch, cutting dimensions, perforating dimensions, cinematography, ISO 491.

FAQ

Q: What is this standard?

A: ISO 491:2002 is an International Standard that specifies cutting and perforating dimensions and related tolerances for 35 mm unexposed motion‑picture and magnetic film.

Q: What does it cover?

A: It covers nominal film width, perforation pitch and geometry, types of perforations, measurement/conditioning requirements, and includes normative tables and informative annex material on dimensional stability and low‑shrinkage film.

Q: Who typically uses it?

A: Manufacturers of raw film stock, perforating/slitting equipment vendors, film laboratories, camera/printer/projector designers, archiving professionals and anyone needing interoperable 35 mm film physical dimensions.

Q: Is it current or superseded?

A: ISO 491:2002 superseded ISO 491:1995 and, according to ISO's record, the 2002 edition was reviewed and confirmed (it remains the published edition as reviewed in ISO's lifecycle). Users should check national adoption or later reviews for any amendments.

Q: Is it part of a series?

A: Yes — it is part of the cinematography family of ISO standards prepared by ISO/TC 36 and is intended to be used alongside related standards that define film image areas, sound‑track positions and other dimensional characteristics for motion‑picture film.

Q: What are the key keywords?

A: 35 mm, perforation, pitch, cutting dimensions, magnetic film, cinematography, film stability, ISO 491.