Overview
ISO 359:1983 - "Cinematography - Projectable image area on 16 mm motion‑picture prints - Dimensions and location" is an International Standard (second edition, 1983) that defines the maximum projectable image area and its position on 16 mm motion‑picture prints intended for projection. The document sets geometric limits and reference datums used when preparing, printing, projecting, restoring, or manufacturing equipment for 16 mm film.
Key topics and technical requirements
- Scope: Specifies dimensions and location of the maximum projectable image area on 16 mm motion‑picture prints for motion‑picture projectors.
- Reference edge: A defined datum (reference edge) is used to locate the projectable area; this reference is for measurement and is not necessarily the film edge used by transport mechanisms.
- Projector aperture vs. projectable area: Dimensions given (A, D, H, etc.) define the maximum image area available on the film for projection. These values do not prescribe the physical aperture‑plate opening of a specific projector, which may vary with optical path and projector design.
- Actual projected area: The standard recognizes the projected image may be smaller than the maximum and may be non‑rectangular. The recommended practice is to use the largest appropriately shaped geometric figure that fits within the specified limits.
- Corner radius: When projector apertures define the screen outline, corner rounding is customary. The recommended maximum corner radius at the film plane is 0.5 mm (0.02 in).
- Key dimensions (from the standard):
- A (minimum): 3.10 mm (0.122 in)
- B (reference): 9.65 mm (0.380 in)
- C (reference): 7.98 mm (0.314 in)
- D (maximum): 12.85 mm (0.506 in)
- H (maximum): 7.26 mm (0.286 in)
- J = K (nominally)
- (E is a derived value given for information)
Applications and who uses it
- Film laboratories and print houses: to ensure prints conform to standardized image placement and maximize compatibility with projection equipment.
- Projection equipment manufacturers and service technicians: to design and set apertures and gate tolerances for 16 mm projectors.
- Archivists and film restorers: to position scanned image frames, crop consistently, and preserve intended framing when digitizing or restoring 16 mm material.
- Cinematographers and post‑production facilities: for consistency in framing, masking, and transfer workflows.
- Standards bodies and quality assurance teams: to reference a common dimensional baseline for 16 mm theatrical and educational projection.
Related standards
- ISO 1223 (covers picture areas for motion‑picture films and slides for television and related positioning/dimensions) - ISO 359 references ISO 1223 for related image‑area guidance.
Keywords: ISO 359:1983, 16 mm film, projectable image area, motion‑picture prints, projection dimensions, cinematography standard, projector aperture, film restoration.