ISO 8478:2017
(Main)Optics and photonics - Camera lenses - Measurement of ISO spectral transmittance
Optics and photonics - Camera lenses - Measurement of ISO spectral transmittance
ISO 8478:2017 specifies a method for measuring the spectral transmittance of camera lenses. It describes particular conditions for measuring the axial spectral transmittance, over a wavelength range from 350 nm to 700 nm, of camera lenses which are intended to be used mainly for taking pictures of very distant objects. If the spectral transmittance values are used exclusively for the calculation of the ISO colour contribution index (see ISO 6728) throughout ISO 8478:2017, the wavelength range reads 370 nm to 680 nm. ISO 8478:2017 is also applicable to mirror lenses (see Annex A).
Optique et photonique — Objectifs photographiques — Mesurage du facteur spectral de transmission ISO
General Information
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Overview
ISO 8478:2017 - Optics and photonics - Camera lenses - Measurement of ISO spectral transmittance - specifies a standardized method to measure the spectral transmittance of camera lenses. The standard defines conditions and apparatus for measuring axial transmittance for lenses intended mainly for imaging distant objects over the wavelength range 350 nm to 700 nm (or 370 nm to 680 nm when values are used exclusively for the ISO colour contribution index). It is also applicable to mirror lenses (see Annex A).
Key topics and requirements
- Measurement principle: Determine spectral transmittance τλ by measuring incident radiant flux Φi,λ and transmitted radiant flux Φτ,λ and calculating τλ = Φτ,λ / Φi,λ.
- Wavelength range & resolution: 350–700 nm nominal; 10 nm wavelength interval and bandwidth required (20 nm allowed when spectral variation < 0.2%/nm). For ISO colour contribution index (ISO CCI) use 370–680 nm and 10 nm intervals.
- Optical setup: Light source → condenser → monochromator (double preferred) or narrow-band filters → adjustable aperture stop → collimator (lens or off‑axis paraboloid mirror) → integrating sphere → detector.
- Beam geometry: Use a collimated beam along the optical axis filling the central half diameter (50% ±5%) of the lens entrance pupil at the lens’s minimum f‑number. Collimator focal length ≥ 30× monochromator exit slit length.
- Integrating sphere & detector: Sphere radius and port size chosen to keep beam location/diameter consistent with and without lens (±50%). Internal coating should be high, non‑selective reflectance 350–700 nm. Detector responsivity must be calibrated across the measuring range and physically matched to the sphere surface.
- Procedure & presentation: Measure incident and transmitted signals at each wavelength, compute ISO/τλ(), present values with two decimal places, state measurement error and provide lens metadata (brand, manufacturer, serial number, focal length, f‑number, measurement date, cleaning notes).
- Mirror lenses (Annex A): Uses same apparatus with a movable integrating sphere; for annular pupils adjust beam to half the annular radial width and repeat measurements at three mirror orientations.
Applications - who uses it
- Optical and lens manufacturers for product verification and quality control.
- Calibration and test laboratories performing standardized camera lens measurements.
- R&D and photonics researchers comparing lens coatings and materials.
- Camera OEMs and QA teams ensuring spectral performance for imaging systems.
- Use cases include colorimetric calculations, spectral characterization for imaging pipelines, and compliance testing.
Related standards
- ISO 6728 - Photography - Camera lenses - Determination of ISO colour contribution index (ISO/CCI) - referenced for colour index calculations.
Frequently Asked Questions
ISO 8478:2017 is a standard published by the International Organization for Standardization (ISO). Its full title is "Optics and photonics - Camera lenses - Measurement of ISO spectral transmittance". This standard covers: ISO 8478:2017 specifies a method for measuring the spectral transmittance of camera lenses. It describes particular conditions for measuring the axial spectral transmittance, over a wavelength range from 350 nm to 700 nm, of camera lenses which are intended to be used mainly for taking pictures of very distant objects. If the spectral transmittance values are used exclusively for the calculation of the ISO colour contribution index (see ISO 6728) throughout ISO 8478:2017, the wavelength range reads 370 nm to 680 nm. ISO 8478:2017 is also applicable to mirror lenses (see Annex A).
ISO 8478:2017 specifies a method for measuring the spectral transmittance of camera lenses. It describes particular conditions for measuring the axial spectral transmittance, over a wavelength range from 350 nm to 700 nm, of camera lenses which are intended to be used mainly for taking pictures of very distant objects. If the spectral transmittance values are used exclusively for the calculation of the ISO colour contribution index (see ISO 6728) throughout ISO 8478:2017, the wavelength range reads 370 nm to 680 nm. ISO 8478:2017 is also applicable to mirror lenses (see Annex A).
ISO 8478:2017 is classified under the following ICS (International Classification for Standards) categories: 37.040.10 - Photographic equipment. Projectors. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 8478:2017 has the following relationships with other standards: It is inter standard links to ISO 8478:1996. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase ISO 8478:2017 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.
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 8478
Second edition
2017-11
Optics and photonics — Camera
lenses — Measurement of ISO spectral
transmittance
Optique et photonique — Objectifs photographiques — Mesurage du
facteur spectral de transmission ISO
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus . 2
5 Conditions. 3
6 Procedure. 4
7 Presentation of the results . 5
Annex A (normative) Method for measuring spectral transmittance of mirror lenses .6
Bibliography . 8
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee
SC 1, Fundamental standards.
This second edition cancels and replaces the first edition (ISO 8478:1996), of which it constitutes a
minor revision.
The main changes compared to the previous edition are as follows:
— the document has been updated to current drafting rules;
— A.2 b) has been adjusted.
iv © ISO 2017 – All rights reserved
Introduction
This document describes a preferred method for the measurement of spectral transmittance.
Alternative methods may be used, provided that the method gives the same result as that obtained
according to this document within the tolerances allowed by it. In the case of lenses with very long or
short focal lengths and in large aperture lenses, care should be taken to maintain the ideal integration
properties of the integrating sphere.
Spectral transmittance of the lens under test may vary with the diameter of the incident beam and with
the angle of incidence of the beam. In order to obtain uniform results, this document specifies that the
measurement is to be made with a collimated beam incident upon the lens along its optical axis, and
filling the central half diameter of its entrance pupil at its minimum f-number.
In the case of lenses with very long or short focal lengths, the measuring method specified in this
document may not be applicable due to the difficulty in preparing a very big or very small integrating
sphere. In such a case, an alternative method may be used, provided that it gives the same result as that
obtained according to this document within the tolerances allowed by this document.
Annex A, which forms an integral part of this document, is provided to give a particular method for
measuring the spectral transmittance of mirror lenses.
INTERNATIONAL STANDARD ISO 8478:2017(E)
Optics and photonics — Camera lenses — Measurement of
ISO spectral transmittance
1 Scope
This document specifies a method for measuring the spectral transmittance of camera lenses. It
describes particular conditions for measuring the axial spectral transmittance, over a wavelength
range from 350 nm to 700 nm, of camera lenses which are intended to be used mainly for taking
pictures of very distant objects.
If the spectral transmittance values are used exclusively for the calculation of the ISO colour contribution
index (see ISO 6728) throughout this document, the wavelength range reads 370 nm to 680 nm.
This document is also applicable to mirror lenses (see Annex A).
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
photographic lens
lens used for recording the image of an object on photosensitive material, such as a camera or
enlarging lens
Note 1 to entry: A projection lens is not a photographic lens.
3.2
camera lens
lens attached to a still camera used for taking pictures of an object
3.3
spectral transmittance of a lens
transmittance denoted by τλ() and defined by the formula
Φ
τλ,
τλ()=
Φ
i,λ
where
is the transmitted radiant flux of wavelength, λ;
Φ
τλ,
Φ
is the corresponding incident radiant flux of wavelength, λ.
i ,λ
4 Apparatus
The apparatus (see Figure 1) shall consist of a light source, a condenser lens, a monochromator (or
narrow bandwidth filters, in limited applications), an aperture stop, a collimator and an integrating
sphere together with a photoelectric detector system.
NOTE Narrow-band filters are subject to errors due to inter-reflections with other components.
...
ISO 8478:2017 is a standard that outlines a method for measuring the spectral transmittance of camera lenses. This standard specifically focuses on measuring the axial spectral transmittance of lenses used for capturing images of distant objects. The measurement is conducted over a wavelength range of 350 nm to 700 nm, or 370 nm to 680 nm if the values are used for calculating the ISO colour contribution index. The standard also applies to mirror lenses as outlined in Annex A.
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