ISO 2240:2003

Photography - Colour reversal camera films - Determination of ISO speed

ISO 2240:2003 specifies the method for determining the ISO speed of colour reversal camera films producing continuous-tone pictorial images that are intended to be viewed on transparency illuminators or by projection as slides. It also applies to 8 mm and 16 mm motion-picture films used in non-professional applications. ISO 2240:2003 is not applicable to professional motion-picture films regardless of their applications.

Photographie — Films de prise de vue inversibles en couleur — Détermination de la sensibilité ISO

Photography - Colour reversal camera films - Determination of ISO speed

General Information

• Status: Published
• Publication Date: 21-Oct-2003
• ICS: 37.040.20 - Photographic paper, films and plates. Cartridges
• Technical Committee: ISO/TC 42 - Photography
• Drafting Committee: ISO/TC 42/WG 3 - Image measurement, viewing and sensitometry
• Current Stage: 9093 - International Standard confirmed
• Start Date: 05-Jun-2025
• Completion Date: 13-Dec-2025
• Ref Project: SIST ISO 2240:2004 - Photography -- Colour reversal camera films -- Determination of ISO speed

Relations

• Revised: SIST ISO 2240:1997 - Photography -- Colour reversal camera films -- Determination of ISO speed
• Effective Date: 12-May-2008
• Revises: ISO 2240:1994 - Photography - Colour reversal camera films - Determination of ISO speed
• Effective Date: 15-Apr-2008

Overview

ISO 2240:2003 specifies the standardized method for determining the ISO speed of colour reversal camera films (slide/transparency films). It applies to continuous‑tone pictorial films intended for viewing on transparency illuminators or by projection, and to 8 mm and 16 mm motion‑picture films used in non‑professional applications. This edition replaces ISO 2240:1994 and defines how to measure and report film speed so that exposure meters, camera automatic exposure systems and users can obtain predictable results.

Key topics and technical requirements

• Scope: Colour reversal (positive) films for transparencies and non‑professional 8/16 mm motion‑picture films; not for professional motion‑picture films.
• Sampling & storage: Test several batches; store samples per manufacturer recommendations to simulate normal user age before testing.
• Environmental conditions: Equilibrate samples at (23 ± 2) °C and (50 ± 5) % RH during exposure and before processing.
• Sensitometry & exposure:
  • Use a non‑intermittent, illuminance‑scale sensitometer.
  • Use illuminants conforming to ISO 7589 (daylight, tungsten, photoflood). Specify illuminant in instructions.
  • Exposure time for speed determination: 5 s to 1/1 000 s (reciprocity effects should be noted).
  • If filters are used in-camera, report an “equivalent” speed; ISO speed applies without filters.
• Modulation requirements: Limits on spectral diffuse transmission modulation across 400–700 nm (and 360–400 nm allowances) to ensure uniformity of test exposures.
• Processing:
  • Processing procedures are not prescribed - use manufacturer‑recommended processes.
  • Timing between exposure and processing: general‑purpose films 5–10 days, professional films 4 h–7 days.
  • Film speed is dependent on processing; processing conditions must be reported with quoted speed.
• Densitometry:
  • Measure ISO standard visual diffuse transmission density per ISO 5‑2 (geometric) and ISO 5‑3 (spectral).
  • Readings in uniform image areas (≥1 mm from edges).
• Evaluation & calculation:
  • Plot density vs. log10(H) to obtain a sensitometric curve.
  • Define point P at 0.20 above minimum density and point S at 2.00 above minimum density. The slope between P and S should be between −1.4 and −1.8.
  • Compute log Hm from H_P and H_S, average log Hm across batches, then convert to ISO speed using the standard scale (Table 1).
  • Accuracy: absolute error in log H must be < 0.05.
• Marking: Report as e.g. ISO 100, ISO 21°, or ISO 100/21°.

Applications and who uses it

ISO 2240:2003 is aimed at:

• Film manufacturers and QA labs for product certification, batch testing and labeling of colour reversal films.
• Sensitometry and densitometry labs establishing ISO speed for new film emulsions or process variants.
• Camera and exposure‑meter manufacturers referencing standardized film speed to calibrate automatic exposure controls (see ISO 2721 and ISO 2720).
• Photographic testing services and technical documentation teams producing exposure guidance for slide projection and transparency viewing.

Practical benefits include consistent exposure recommendations, reliable inter‑lab comparisons, and standardized product marking for marketing and user guidance.

Related standards

Relevant references for implementation and measurement:

• ISO 5‑2, ISO 5‑3 (densitometry conditions)
• ISO 7589 (sensitometry illuminants)
• ISO 2720, ISO 2721 (exposure meters & camera controls)
• ISO 3664 (viewing conditions)
• ISO 2910 (screen luminance for projection)

Keywords: ISO 2240:2003, colour reversal camera films, ISO speed determination, sensitometry, densitometry, exposure, film speed, transparency, slide film, 8 mm, 16 mm.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2004
Photography - Colour reversal camera films - Determination of ISO speed
Photography -- Colour reversal camera films -- Determination of ISO speed
Photographie -- Films de prise de vue inversibles en couleur -- Détermination de la
sensibilité ISO
Ta slovenski standard je istoveten z: ISO 2240:2003
ICS:
37.040.20 )RWRJUDIVNLSDSLUILOPLLQ Photographic paper, films
IRWRJUDIVNHSORãþH)LOPVNL and cartridges
]YLWNL
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 2240
Fourth edition
2003-10-15
Photography — Colour reversal camera
films — Determination of ISO speed
Photographie — Films de prise de vue inversibles en couleur —
Détermination de la sensibilité ISO

Reference number
©
ISO 2003
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 2003
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 [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2003 — 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 2240 was prepared by Technical Committee ISO/TC 42, Photography.
This fourth edition cancels and replaces the third edition (ISO 2240:1994), which has been technically revised.
Introduction
The ISO speeds are intended to provide correct exposures with exposure meters conforming to ISO 2720,
and, where applicable, automatic exposure controls for cameras conforming to ISO 2721; the resultant
camera exposure will normally lead to colour transparencies or motion pictures of the best quality. For an
average scene and average camera, the indicated camera exposure will be approximately midway between
the least exposure and the greatest exposure required to produce transparencies and motion-picture films
suitable for viewing at normal luminance levels.
For the purpose of this International Standard, the normal luminance of transparency illuminators is assumed
to be that described in ISO 3664 with a ratio of direct-to-ambient luminance of about 40:1. The normal
luminance of transparency projection screens is assumed to be about 137 cd/m .
Screen luminance of 8 mm Type R and 8 mm Type S (Super-8) motion-picture film projection is assumed to
2 2
range from approximately 40 cd/m (see ISO 2910) to 62 cd/m . Therefore, it may be desirable to increase
exposure by 25 % above that obtained by using the speed derived by following the sensitometric procedure
described in this International Standard. Many camera manufacturers design and calibrate their 8 mm Type R
and 8 mm Type S motion-picture cameras with an adjustment which permits more exposure to compensate
for the lower screen luminance of the usual projection conditions (see ISO 2721).

iv © ISO 2003 — All rights reserved

INTERNATIONAL STANDARD ISO 2240:2003(E)

Photography — Colour reversal camera films — Determination
of ISO speed
1 Scope
This International Standard specifies the method for determining the ISO speed of colour reversal camera
films producing continuous-tone pictorial images that are intended to be viewed on transparency illuminators
or by projection as slides. It also applies to 8 mm and 16 mm motion-picture films used in non-professional
applications.
This International Standard is not applicable to professional motion-picture films regardless of their
applications.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 5-2, Photography — Density measurements — Part 2: Geometric conditions for transmission density
ISO 5-3, Photography — Density measurements — Part 3: Spectral conditions
ISO 7589, Photography — Illuminants for sensitometry — Specifications for daylight, incandescent tungsten
and printer
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
exposure
H
time integral of illuminance on the film
[8]
NOTE 1 In the International lighting vocabulary , H is defined as the luminous exposure. In this International Standard,
"luminous exposure" is simply referred to as "exposure".
NOTE 2 Exposure is measured in lux seconds.
NOTE 3 Exposure is often expressed in log H units.
3.2
speed
quantitative measure of the response of the photographic material to radiant energy for the specified
conditions of exposure, processing, density measurement and analysis
3.3
minimum density
minimum density value obtainable following the process used in the ISO speed determination
4 Sampling and storage
In determining the ISO speed of a product, it is important that the samples evaluated yield the average results
obtained by users. This requires evaluating several different batches periodically under the conditions
specified in this International Standard. Prior to evaluation, the samples shall be stored according to the
manufacturers' recommendations for a length of time to simulate the average age at which the product is
normally used. To assure that all components of variance are included in the sampling plan, it is
[7]
recommended that procedures such as those outlined in ISO Standards Handbook be used. The objective
in selecting and storing samples as described above is to ensure the film characteristics are representative of
those obtained by a photographer at the time of use.
5 Test method
5.1 Principle
Samples are exposed and processed in the manner specified below. Density measurements are obtained
from the resultant images to produce a sensitometric curve from which values are taken and used to
determine ISO speed.
5.2 Safelights
To eliminate the possibility of safelight illumination affecting the sensitometric results, all films shall be handled
in complete darkness during sample preparation, exposing and processing.
5.3 Exposure
5.3.1
...

INTERNATIONAL ISO
STANDARD 2240
Fourth edition
2003-10-15
Photography — Colour reversal camera
films — Determination of ISO speed
Photographie — Films de prise de vue inversibles en couleur —
Détermination de la sensibilité ISO

Reference number
©
ISO 2003
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 2003
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 [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2003 — 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 2240 was prepared by Technical Committee ISO/TC 42, Photography.
This fourth edition cancels and replaces the third edition (ISO 2240:1994), which has been technically revised.
Introduction
The ISO speeds are intended to provide correct exposures with exposure meters conforming to ISO 2720,
and, where applicable, automatic exposure controls for cameras conforming to ISO 2721; the resultant
camera exposure will normally lead to colour transparencies or motion pictures of the best quality. For an
average scene and average camera, the indicated camera exposure will be approximately midway between
the least exposure and the greatest exposure required to produce transparencies and motion-picture films
suitable for viewing at normal luminance levels.
For the purpose of this International Standard, the normal luminance of transparency illuminators is assumed
to be that described in ISO 3664 with a ratio of direct-to-ambient luminance of about 40:1. The normal
luminance of transparency projection screens is assumed to be about 137 cd/m .
Screen luminance of 8 mm Type R and 8 mm Type S (Super-8) motion-picture film projection is assumed to
2 2
range from approximately 40 cd/m (see ISO 2910) to 62 cd/m . Therefore, it may be desirable to increase
exposure by 25 % above that obtained by using the speed derived by following the sensitometric procedure
described in this International Standard. Many camera manufacturers design and calibrate their 8 mm Type R
and 8 mm Type S motion-picture cameras with an adjustment which permits more exposure to compensate
for the lower screen luminance of the usual projection conditions (see ISO 2721).

iv © ISO 2003 — All rights reserved

INTERNATIONAL STANDARD ISO 2240:2003(E)

Photography — Colour reversal camera films — Determination
of ISO speed
1 Scope
This International Standard specifies the method for determining the ISO speed of colour reversal camera
films producing continuous-tone pictorial images that are intended to be viewed on transparency illuminators
or by projection as slides. It also applies to 8 mm and 16 mm motion-picture films used in non-professional
applications.
This International Standard is not applicable to professional motion-picture films regardless of their
applications.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 5-2, Photography — Density measurements — Part 2: Geometric conditions for transmission density
ISO 5-3, Photography — Density measurements — Part 3: Spectral conditions
ISO 7589, Photography — Illuminants for sensitometry — Specifications for daylight, incandescent tungsten
and printer
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
exposure
H
time integral of illuminance on the film
[8]
NOTE 1 In the International lighting vocabulary , H is defined as the luminous exposure. In this International Standard,
"luminous exposure" is simply referred to as "exposure".
NOTE 2 Exposure is measured in lux seconds.
NOTE 3 Exposure is often expressed in log H units.
3.2
speed
quantitative measure of the response of the photographic material to radiant energy for the specified
conditions of exposure, processing, density measurement and analysis
3.3
minimum density
minimum density value obtainable following the process used in the ISO speed determination
4 Sampling and storage
In determining the ISO speed of a product, it is important that the samples evaluated yield the average results
obtained by users. This requires evaluating several different batches periodically under the conditions
specified in this International Standard. Prior to evaluation, the samples shall be stored according to the
manufacturers' recommendations for a length of time to simulate the average age at which the product is
normally used. To assure that all components of variance are included in the sampling plan, it is
[7]
recommended that procedures such as those outlined in ISO Standards Handbook be used. The objective
in selecting and storing samples as described above is to ensure the film characteristics are representative of
those obtained by a photographer at the time of use.
5 Test method
5.1 Principle
Samples are exposed and processed in the manner specified below. Density measurements are obtained
from the resultant images to produce a sensitometric curve from which values are taken and used to
determine ISO speed.
5.2 Safelights
To eliminate the possibility of safelight illumination affecting the sensitometric results, all films shall be handled
in complete darkness during sample preparation, exposing and processing.
5.3 Exposure
5.3.1 Sample conditions
During exposure, the samples shall be equilibrated with air at a temperature of (23 ± 2) °C and a relative
humidity of (50 ± 5) %.
5.3.2 Type of sensitometer
The sensitometer shall be a non-intermittent, illuminance-scale type.
5.3.3 Radiant energy quality
The appropriate illuminant for the particular film type being exposed shall conform to the specification given in
ISO 7589. ISO speed may be determined using ISO se
...