ISO 466:1976

Overview

ISO 466:1976 - "Cinematography - Image produced by 16 mm motion‑picture camera aperture - Position and dimensions" defines the location and dimensional tolerances of the image area produced by a 16 mm camera aperture. Published by ISO’s Technical Committee ISO/TC 36 (Cinematography), this second edition (1976) updates the earlier 1965 edition and was later amended to note additional member approvals. The standard describes the image area relative to a reference edge and the optical axis, and specifies measurements on unshrunk 16 mm film.

Key topics and technical requirements

• Image area position and dimensions: The standard gives the nominal, maximum and minimum dimensions and the centre location of the intended picture image relative to the reference edge and optical axis.
• Reference edge datum: Dimensions are specified with respect to a “reference edge” of the film; the standard clarifies that this reference serves as the datum even if that edge is not the guided edge in a camera.
• Unshrunk film basis: All dimensions and tolerances are stated for unshrunk 16 mm motion‑picture film to ensure consistency during manufacture and inspection.
• Sample dimensional values: The document includes concrete dimension values and relationships, for example: A (max) = 2.95 mm (0.116 in), D = 13.00 mm (0.512 in) for certain configurations, R (max) ≈ 0.50 mm, and formulaic relationships such as E = F + 0.20 mm (0.008 in). (See the standard for the full table of nominal/min/max values and notes.)
• Film orientation: The diagram and notes show the film as viewed from inside the camera looking toward the lens, with the photographic layer away from the observer.
• Special cases: Notes address specific uses such as negatives carrying a photographic soundtrack where dimensional requirements may differ.

Applications and who uses it

• Camera and lens manufacturers - to design apertures, registration pins and transport systems that produce consistent image framing on 16 mm film.
• Film laboratory and processing equipment designers - for cutting, perforating and handling tolerances tied to image placement.
• Cinematographers and camera technicians - to verify camera alignment and ensure intended framing and optical axis placement.
• Restoration and archival specialists - to assess original framing and to maintain compatibility between historical equipment and modern reproduction/projecting systems.
• Standardization bodies and procurement teams - to reference a recognized benchmark when specifying 16 mm motion‑picture equipment.

Related standards

• ISO 25 (Cinematography - Camera gauge of 16 mm motion‑picture film - Specifications)
• ISO 69 (Cinematography - Cutting and perforating dimensions)
• ISO 359 (Cinematography - Projectable image area on 16 mm motion‑picture prints)

For exact tolerances, figures and the full measurement table, consult the ISO 466:1976 document. Keywords: ISO 466:1976, 16 mm film, cinematography standard, camera aperture image area, film dimensions, reference edge, unshrunk film.