ISO 20859:2005
(Main)Cinematography - Spectral response of photographic audio reproducers for analog dye sound tracks on 35 mm film
Cinematography - Spectral response of photographic audio reproducers for analog dye sound tracks on 35 mm film
ISO 20859:2005 specifies the spectral response of the photographic audio reproducer light source and receptor as a unit, including any optical filtering that can be interposed. The analog sound track formats suitable for reproduction using such a reproducer include the cyan dye-only track (without redevelopment of silver) and both conventional and "high magenta" soundtracks (with redevelopment of silver).
Cinématographie — Réponse spectrale de lecteurs audio avec des pistes sonores analogiques de couleurs sur film de tirage 35 mm
General Information
Overview
ISO 20859:2005 - "Cinematography - Spectral response of photographic audio reproducers for analog dye sound tracks on 35 mm film" - defines the required spectral behaviour of a photographic audio reproducer taken as a unit (light source, any interposed optical filtering, and receptor). The standard covers reproduction of analog 35 mm sound tracks including cyan dye-only, conventional, and high-magenta formats, and is intended to ensure reliable, high-quality playback across projector and reader designs.
Key topics and technical requirements
- Scope: specifies the combined spectral response of light source + filter + receptor for photographic audio reproducers intended for 35 mm analog dye sound tracks.
- Peak response: the combined unit shall have a peak (maximum) response at 660 nm with an allowed tolerance of +20 / −30 nm.
- Out‑of‑band rejection: the integrated response to wavelengths greater than 800 nm must be less than 5% of the total integrated response measured from 400 nm to 800 nm.
- Formats covered: applies to cyan dye-only tracks (no silver redevelopment) and to conventional and high-magenta tracks (with silver redevelopment).
- Design implications: the unit may include optical filtering, and is intended to support a transition from infrared-sensitive, tungsten-based reproducers (used for silver tracks) to red-sensitive reproducers using LEDs or lasers for dye tracks.
Practical applications and users
Who uses ISO 20859:2005:
- Film projector and audio reproducer manufacturers designing light sources, filters, and sensors for 35 mm playback.
- Film laboratories and post-production houses establishing release-print processes for dye and high-magenta soundtracks.
- Cinema operators and technicians ensuring playback compatibility and sound quality during conversion from silver-based to dye-only prints.
- Archive and preservation specialists specifying playback equipment to minimise damage and ensure faithful reproduction.
- Standards bodies and test labs validating conformance of reproducers.
Benefits and practical outcomes:
- Ensures optimal modulation of cyan dye sound tracks by matching reproducer spectral response to dye absorption, reducing cross‑modulation distortion and preserving high-frequency response and SNR.
- Facilitates environmental improvements by enabling dye-only workflows (eliminating silver redevelopment and associated effluent).
- Encourages use of longer‑life solid-state red sources (LEDs/lasers) for improved reliability.
Related standards
Prepared by ISO/TC 36 (Cinematography). For broader context, consult other ISO cinematography and optical measurement publications and national implementation guidance produced by ISO member bodies.
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 20859
First edition
2005-06-15
Cinematography — Spectral response of
photographic audio reproducers for
analog dye sound tracks on 35 mm film
Cinématographie — Réponse spectrale de lecteurs audio avec des
pistes sonores analogiques de couleurs sur film de tirage 35 mm
Reference number
©
ISO 2005
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2005
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2005 – All rights reserved
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 20859 was prepared by Technical Committee ISO/TC 36, Cinematography.
INTERNATIONAL STANDARD ISO 20859:2005(E)
Cinematography — Spectral response of photographic audio
reproducers for analog dye sound tracks on 35 mm film
1 Scope
This International Standard specifies the spectral response of the photographic audio reproducer
...
Frequently Asked Questions
ISO 20859:2005 is a standard published by the International Organization for Standardization (ISO). Its full title is "Cinematography - Spectral response of photographic audio reproducers for analog dye sound tracks on 35 mm film". This standard covers: ISO 20859:2005 specifies the spectral response of the photographic audio reproducer light source and receptor as a unit, including any optical filtering that can be interposed. The analog sound track formats suitable for reproduction using such a reproducer include the cyan dye-only track (without redevelopment of silver) and both conventional and "high magenta" soundtracks (with redevelopment of silver).
ISO 20859:2005 specifies the spectral response of the photographic audio reproducer light source and receptor as a unit, including any optical filtering that can be interposed. The analog sound track formats suitable for reproduction using such a reproducer include the cyan dye-only track (without redevelopment of silver) and both conventional and "high magenta" soundtracks (with redevelopment of silver).
ISO 20859:2005 is classified under the following ICS (International Classification for Standards) categories: 37.060.20 - Motion picture films. Cartridges. The ICS classification helps identify the subject area and facilitates finding related standards.
You can purchase ISO 20859:2005 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of ISO standards.
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...