ISO 11315-1:1997

ISO
INTERNATIONAL
11315-1
STANDARD
First edition
1997-11-15
Photography — Projection in indoor
rooms —
Part 1:
Screen illumination test for still projectors
Photographie — Projection en salles —
Partie 1: Essai de luminosité de l'écran pour projecteurs fixes
A
Reference number
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.
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.
International Standard ISO 11315-1 was prepared by Technical Committee
ISO/TC 42, Photography.
It cancels and replaces ISO 8341:1989, of which it constitutes a technical
revision.
ISO 11315 consists of the following parts, under the general title
Photography — Projection in indoor rooms:
— Part 1: Screen illumination test for still projectors
— Part 2: Screen luminance test for still and video projection
— Part 3: Projection reflecting screens
— Part 4: Reflecting projection screens — Classification and
measurement of reflected screen luminance levels and sound
attenuation
Annexes A and B of this part of ISO 11315 are for information only.
©  ISO 1997
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 the publisher.
International Organization for Standardization
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ii
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INTERNATIONAL STANDARD  ISO ISO 11315-1:1997(E)
Photography — Projection in indoor rooms —
Part 1:
Screen illumination test for still projectors
1 Scope
This part of ISO 11315 specifies a laboratory measuring method for determining the utilised flux
of the projector and the uniformity of screen illuminance in darkened projection rooms for all
types of purely optical still projection.
A standardized uniform light-measuring system allows comparison of screen illuminance values
for different projection systems used alternately in practical use.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute
provisions of this part of ISO 11315. At the time of publication, the editions indicated were valid.
All standards are subject to revision, and parties to agreements based on this part of
ISO 11315 are encouraged to investigate the possibility of applying the most recent editions of
the standards indicated below. Members of IEC and ISO maintain registers of currently valid
International Standards.
CIE No. 15.2:1986, Colorimetry (2nd edition).
CIE No. 17.4:1987, International Lighting Vocabulary [Same edition as IEC 50(845):
International Electrotechnical Vocabulary, Chapter 845: Lighting.]
CIE No. 18.2:1983, .
The Basis of Physical Photometry
CIE No. 69:1987, Methods of Characterizing Illuminance Meters and Luminance Meters -
Performance, Characteristics and Specifications.
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ISO
3 Definitions
For the purposes of this part of ISO 11315, the following definitions apply.
3.1 illumination: The application of visible radiation (light) to an object.
[CIE-Publ. No. 17]
The quantity derived from radiant flux by evaluating the
3.2 luminous flux; light output:
radiation according to its action upon a selective receptor, the spectral sensitivity of which is
defined by the standard spectral luminous efficiencies.
[CIE-Publ. No. 17]
3.3 utilised flux: The luminous flux received on one side of the reference surface.
[CIE-Publ. No. 17]
3.4 still projection: All projection methods with one or more projectors for slides, overhead-
projection transparencies, episcopic pictures for projection and transparent LCDs.
3.5 dark-room projection: An indoor room without any additional room lighting, except safety-
lights for steps, emergency exits, etc.
3.6 uniformity ratio, g : The ratio of the lowest measured illuminance/luminance to the highest
measured illuminance/luminance, e.g. E /E (x 100 in %).
min max
[CIE-Publ. No. 17]
4 Preparation for photometric measurements
4.1 Preconditioning
Before the commencement of any test, the projector shall be conditioned by being kept under
the environmental conditions of the testing laboratory for at least 8 h.
4.2 Projector set-up (light path)
While making the tests, the projector shall be operated with its normal components (e.g. light
source, heat filter, condenser, lens), but without projection material (i.e. slides, films, etc. in the
picture area or aperture plate).
4.3 Voltage, current and frequencies
4.3.1 The projector shall be operated from an adjustable power supply adjusted to within
± 0,5 % of the rated voltage of the projector.
While adjusting the supply for tungsten lighting or non-controllable discharge lamps, the voltage
shall be measured at the supply socket to which the recommended power supply cord of the
projector is connected. The frequency of the power supply shall match the manufacturer's rating
for the projector.
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ISO
For controllable xenon-discharge lamps, the current shall be the nominal value (according to
the data of the lamp-manufacturer) ± 0,5 %. In the case of xenon discharge lamps with a
relatively vast luminous flux, the measurement shall be made through a highlight film
(approximately D = 0,1-0,15 where D is the film thickness, in millimetres) and with half of the
nominal current. The value of the nominal luminous flux shall be calculated from the above
parameters.
4.3.2 If the projector (equipped with tungsten lighting or non-controllable discharge lamps) is
suitable for use at different voltages and/or frequencies, the measurements for determining the
luminous flux shall be made either at each adjustable voltage ± 0,5 % and its related frequency,
or at least at a selection of characteristic voltages and frequencies. When selecting the voltages
and frequencies, consideration shall be given to the main usage of the projector in practice, and
the conditions under which extreme differences of the test results might be expected. The
measurements for determining the uniformity of screen illuminance can be made at any position
of the voltage selector with the respective line voltage ± 0,5 % and the related frequency.
4.3.3 For determining the input voltage of the tungsten lamp, the voltage at the lamp holder
shall be measured with the lamp operating, and after the time specified in 4.8 has elapsed.
(When a lamp is provided by a switching power supply, use a true r.m.s voltmeter.)
4.4 Lamp adjustment
The lamp shall be adjusted in the projector according to the operating instructions.
4.5 Cleanliness
The optical elements of the projector shall be free from dust and other contamination.
4.6 Ambient temperature
The ambient temperature in the testing laboratory shall be 23 °C ± 2 °C.
4.7 Projector alignment
The projector shall be positioned so that the projection of its optical axis is normal to the plane
of the screen. (See annex A, note.)
4.8 Stabilization
If the lamp is fed via a transformer or a ballast resistance, the light measurements shall be
started, at the earliest, 20 min after having switched on the lamp, running under normal test
conditions. If the lamp is fed directly by the mains voltage, the measurements can be started
after 5 min.
4.9 Ambient light
The illumination of the screen due to ambient light should not exceed 1 % of the screen
illuminance due to illumination projected through the projector lens during the measurement.
For the reduction of stray light, the use of a black screen is recommended.
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5 Light-measuring equipment
5.1 General
The photometric properties of projectors are described by the luminous flux (see 6.4.2) and by
its uniformity on the projection screen (see clause 7).
5.2 Photometer
The photometer used shall have a spectral response characteristic corresponding to the
CIE 1931
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