SIST EN 61146-2:1999
(Main)Video cameras (PAL/SECAM/NTSC) - Methods of measurement -- Part 2: Two- and three-sensor professional cameras
Video cameras (PAL/SECAM/NTSC) - Methods of measurement -- Part 2: Two- and three-sensor professional cameras
Applies to the assessment of performance of professional colour video cameras equipped with two and three tubes or solid state imagers, user for educational or industrial purposes and in other applications. Defines test patterns, measurement conditions and methods of measurement.
Videokameras (PAL/SECAM/NTSC) - Meßverfahren -- Teil 2: Zwei- und Drei-Sensorkameras für professionelle Anwendung
Caméras vidéo (PAL/SECAM/NTSC) - Méthodes de mesure -- Partie 2: Caméras professionnelles à deux et trois capteurs
S'applique à l'évaluation des performances des caméras vidéo couleur professionnelles équipées de deux et trois tubes ou de systèmes d'imagerie à l'état solide, qui sont utilisés dans l'enseignement ou l'industrie, ainsi que dans d'autres applications. Définit les mires d'essai, les conditions et les méthodes de mesure.
Video cameras (PAL/SECAM/NTSC) - Methods of measurement -- Part 2: Two- and three-sensor professional cameras (IEC 61146-2:1997)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 61146-2:1999
01-april-1999
Video cameras (PAL/SECAM/NTSC) - Methods of measurement -- Part 2: Two- and
three-sensor professional cameras (IEC 61146-2:1997)
Video cameras (PAL/SECAM/NTSC) - Methods of measurement -- Part 2: Two- and
three-sensor professional cameras
Videokameras (PAL/SECAM/NTSC) - Meßverfahren -- Teil 2: Zwei- und Drei-
Sensorkameras für professionelle Anwendung
Caméras vidéo (PAL/SECAM/NTSC) - Méthodes de mesure -- Partie 2: Caméras
professionnelles à deux et trois capteurs
Ta slovenski standard je istoveten z: EN 61146-2:1997
ICS:
33.160.40 Video sistemi Video systems
SIST EN 61146-2:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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NORME
CEI
INTERNATIONALE
IEC
61146-2
INTERNATIONAL
Première édition
STANDARD
First edition
1997-08
Caméras vidéo (PAL/SECAM/NTSC) –
Méthodes de mesure –
Partie 2:
Caméras professionnelles à deux et
trois capteurs
Video cameras (PAL/SECAM/NTSC) –
Methods of measurement –
Part 2:
Two- and three-sensor professional cameras
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CODE PRIX
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PRICE CODE
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Pour prix, voir catalogue en vigueur
For price, see current catalogue
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61146-2 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 11
Clause
1 General. 13
1.1 Scope . 13
1.2 Normative references. 13
1.3 Conditions . 15
1.3.1 Environmental conditions . 15
1.3.2 Conditions of measurements . 15
1.3.3 Reference output levels. 17
2 Video characteristics. 19
2.1 Sensitivity . 19
2.1.1 Reference subject illumination. 19
2.1.2 Reference sensitivity (alternative method) . 23
2.1.3 Minimum subject illumination. 25
2.2 Resolution . 27
2.2.1 Modulation depth. 27
2.2.2 Common resolution . 31
2.3 Signal-to-noise ratio. 31
2.3.1 Characteristics to be specified. 31
2.3.2 Measurement conditions . 33
2.3.3 Method of measurement. 35
2.3.4 Presentation of results . 37
2.4 Waveform distortions (streaking). 37
2.4.1 Characteristics to be specified. 37
2.4.2 Measurement conditions . 37
2.4.3 Method of measurement. 41
2.4.4 Presentation of results . 41
2.5 Gamma and white balance tracking characteristics. 41
2.5.1 Characteristics to be specified. 41
2.5.2 Measurement conditions . 43
2.5.3 Method of measurement. 43
2.5.4 Presentation of results . 45
2.6 Colour and white reproduction non-uniformity . 45
2.6.1 Characteristics to be specified. 45
2.6.2 Measurement conditions . 45
2.6.3 Method of measurement. 45
2.6.4 Presentation of results . 47
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61146-2 © IEC:1997 – 5 –
Clause Page
2.7 Tracking error of white shading . 47
2.7.1 Characteristics to be specified. 47
2.7.2 Measurement conditions . 47
2.7.3 Method of measurement. 49
2.7.4 Presentation of results . 53
2.8 Black shading . 53
2.8.1 Characteristics to be specified. 53
2.8.2 Measurement conditions . 53
2.8.3 Method of measurement. 53
2.8.4 Presentation of results . 53
2.9 White clipping and compression rate . 53
2.9.1 Characteristics to be specified. 53
2.9.2 Measurement conditions . 55
2.9.3 Method of measurement. 55
2.9.4 Presentation of results . 55
2.10 Dynamic range and contrast range . 55
2.10.1 Characteristics to be specified. 55
2.10.2 Method of measurement. 55
2.10.3 Presentation of results . 57
2.11 Colour reproduction . 57
2.11.1 Characteristics to be specified. 57
2.11.2 Measurement conditions . 59
2.11.3 Method of measurement. 63
2.11.4 Calculation. 63
2.11.5 Original colour chip samples . 67
2.11.6 Presentation of results . 67
2.11.7 Camera for which only a composite video signal is available . 67
2.12 Flare. 67
2.12.1 Characteristics to be specified. 69
2.12.2 Measurement conditions . 69
2.12.3 Method of measurement. 71
2.12.4 Presentation of results . 71
3 Other anomalies. 71
3.1 Moires . 71
3.1.1 For a camera which provides R, G, B outputs . 71
3.1.2 For a camera which provides composite video output only . 73
3.2 Lag . 73
3.2.1 Measurement conditions . 73
3.2.2 Method of measurement. 73
3.2.3 Presentation of results . 73
3.3 Sticking (image retention) . 73
3.3.1 Measurement conditions . 73
3.3.2 Method of measurement. 73
3.3.3 Presentation of results . 73
3.4 Blooming . 75
3.4.1 Method of measurement. 75
3.4.2 Presentation of results . 75
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61146-2 © IEC:1997 – 7 –
Clause Page
3.5 Smearing . 75
3.5.1 Method of measurement. 75
3.5.2 Presentation of results . 77
3.6 Registration . 77
3.6.1 Characteristics to be specified. 77
3.6.2 Method of measurement. 77
3.6.3 Alternative method of measurement . 83
3.7 Geometric distortions . 89
3.7.1 Conventional method. 89
3.7.2 Alternative method . 89
Figures
Figure 1 – Equipment arrangement for measurement of sensitivity . 19
Figure 2 – Specification of grey scale test chart . 21
Figure 3 – Equipment arrangement for measurement of resolution . 29
Figure 4 – Specification of the transparent test charts for measurement of
modulation depth. 29
Figure 5 – Equipment arrangement for measurement of signal-to-noise ratio . 33
Figure 6 – Specification of the reflective test chart for measurements signal-to-
noise ratio and white shading . 35
Figure 7 – Equipment arrangement for measurement of waveform distortion . 39
Figure 8 – Specification of the transparent test chart for measurement of streaking . 39
Figure 9 – Examples of waveforms . 41
Figure 10 – Equipment arrangement for measurement of gamma and white balance
tracking characteristics, colour and white reproduction, white clipping
and compression rate, and flare . 43
Figure 11 – Specification of the rectangle . 47
Figure 12 – Equipment arrangement for measurement of tracking error of white
shading . 49
Figure 13 – Waveform of the tracking error of white shading . 51
Figure 14 – Equipment arrangement for measurement of colour reproduction. 59
Figure 15 – Specification of arrangement of colour samples for measurement of
colour reproduction . 61
Figure 16 – Specification of the test chart for measurement of overall flare (average
picture level = 50 %). 69
Figure 17 – Specification of the test chart for measurement of localized flare
(average picture level = 99 %) . 69
Figure 18 – Specification of the transparent test chart for measurement of
smearing and blooming . 75
Figure 19 – Equipment arrangement for measurement of registration (conventional
method) . 79
Figure 20 – Specification of the reflective test chart for measurement of registration
(conventional method) . 81
Figure 21 – Definition of the zones for a conventional method of measurement of
registration. 83
Figure 22 – Equipment arrangement for the alternative method of measurement of
registration. 83
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61146-2 © IEC:1997 – 9 –
Page
Figure 23 – Specification of the V pattern test chart for the alternative
measurement method of registration. 85
Figure 24 – Dimensional specification of V pattern . 85
Figure 25 – Extraction of timing offsets for calculation of registration errors. 87
Figure 26 – Equipment arrangement for measurement of geometric distortion . 91
Figure 27 – Definition of the zones in the V pattern test chart for measurement of
geometric distortion. 91
Figure 28 – Definitions of barrel and pincushion distortion. 93
Annex A Bibliography . 97
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61146-2 © IEC:1997 – 11 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
VIDEO CAMERAS (PAL/SECAM/NTSC) –
METHODS OF MEASUREMENT –
Part 2: Two- and three-sensor professional cameras
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61146-2 has been prepared by subcommittee 100C: Audio, video
and multimedia subsystems and equipment, of IEC technical committee 100: Audio, video and
multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100C/59/FDIS 100C/128/RDV
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
Annex A is for information only.
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61146-2 © IEC:1997 – 13 –
VIDEO CAMERAS (PAL/SECAM/NTSC) –
METHODS OF MEASUREMENT –
Part 2: Two- and three-sensor professional cameras
1 General
1.1 Scope
This part of IEC 61146 applies to the assessment of performance of professional colour video
cameras equipped with two and three tubes or solid state imagers, used for educational or
industrial purposes and in other applications.
This part of IEC 61146 defines test patterns, measurement conditions, and methods of
measurement, so as to enable the comparison of the results of measurements.
The methods of measurement are designed to enable the assessment of the performance of
cameras by using light input from the lens and any electrical outputs of the cameras, for
example, R-G-B signals, Y-C separate signals, and composite video signals.
This standard does not specify limiting values for various parameters.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61146. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 61146 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents listed below. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 61146-1: 1994,
Video cameras (PAL/SECAM/NTSC) – Methods of measurement – Part 1:
Non-broadcast single-sensor cameras
ISO/CIE 10526: 1991, CIE colorimetric standard illuminants
ISO/CIE 10527: 1991, CIE colorimetric standard observers
EBU Techn. 3237: 1983, Methods of measurement of the colorimetric fidelity of television
cameras
Corrigendum (1989)
Supplement 1: 1989,
Measurement procedures
Publication CIE 15.2: 1986, Colorimetry
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61146-2 © IEC:1997 – 15 –
1.3 Conditions
1.3.1 Environmental conditions
All measurements shall be carried out within the environmental conditions specified by the
manufacturer of the camera under assessment.
The environmental conditions during measurement, at least the temperature and the relative
humidity, shall be reported together with the results of measurements.
An adequate warm up time shall be allowed.
1.3.2 Conditions of measurements
The measurements shall be carried out either by measuring the output signals of the device
when the camera is shooting different test charts, depending on the characteristic to be
measured, or by measuring the distortions on a monitor screen.
1.3.2.1 Test charts
All the test charts used for measurement shall be specified with the results, together with the
lighting conditions (illumination intensity, correlated colour temperature, etc.).
The test charts shall be shot by the camera so that the frame limited by the arrows coincides
exactly with the edges of the picture displayed on the video monitor in underscan mode.
The test charts may be either reflective or transparent. Where there is a choice, the reflective
test chart shall be used in questionable cases.
1.3.2.2 Illumination
The illumination of reflective test charts shall be performed by two spotlights with a correlated
+100K
colour temperature of 3 200 K placed at 45° with respect to the perpendicular axis of the
−200K
centre of the test charts, as shown in figure 1.
A uniform illumination should be obtained by adjusting the distance of the spotlights or by
defocusing them. The illumination can also be adjusted by other means without changing the
colour temperature. It is recommended to maintain the supply voltage constant during the
measurements. The light box used for transparent test charts shall be a diffusing surface,
illuminated by a light source with a stabilised power supply.
The subject illumination of the reflective chart shall be 2 000 lx ± 5 %. The luminance of the
diffusion surface of the light box used for a transparent test chart shall be 636 cd/m² ± 5 %.
1.3.2.3 Reference conditions
The camera shall be placed so that its optical axis coincides with the perpendicular passing
through the centre of the test chart, the camera being adjusted for normal operation conditions.
If switching is possible, the measurements should be made in the following setting conditions,
using the standard lens specified by the manufacturer of the camera (see note below), unless
otherwise stated:
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61146-2 © IEC:1997 – 17 –
a) focal length of the lens is adjusted to the mean value corresponding to normal operation;
b) iris is set to f/5,6;
c) white balance is set, manually or automatically, to the position corresponding to the
correlated colour temperature of the illuminant;
d) white balance is further adjusted using a white test chart (see figure 6) with the output
signals as the reference value;
e) bias light is set ON, when applicable;
f) black level corrector is ON, when applicable;
g) flare corrector is ON;
h) black balance is set for an output voltage of 35 mV with lens capped;
i) colour matrixing corrector is OFF;
j) contour corrector is OFF;
k) noise reducer is OFF;
l) aperture correction is OFF;
m) black and white shading correctors are ON and optimized;
n) gamma corrector is set to OFF;
o) gain is set to 0 dB;
p) knee and auto-knee functions are set to OFF where appropriate.
NOTE – If a zoom lens is recommended by the manufacturer, the measurement may be carried out using the
narrowest and the widest angle of the lens. In this case, the type of the lens and the setting should be reported
with measured results.
1.3.2.4 Equipment arrangement
Unless otherwise stated, the equipment arrangement shown in figures 1 or 3 should be used.
The test equipment shall have the following specifications:
a) oscilloscope
– with external television synchronization,
– adjustable delay relative to the field interval,
– marker pulse output which can be used to mark on the monitor the part of the picture
signal which is displayed on the oscilloscope;
b) lightmeter
– with a cosine corrector;
c) video signal outputs shall be properly terminated by 75 Ω.
1.3.3 Reference output levels
Unless otherwise specified, the reference luminance Y and R, G, B output levels are assumed
to be 700 mV peak-to-peak for PAL and SECAM systems, and 714 mV peak-to-peak for NTSC
systems. The level shall be measured from the blanking level to the peak white level.
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61146-2 © IEC:1997 – 19 –
2 Video characteristics
2.1 Sensitivity
2.1.1 Reference subject illumination
2.1.1.1 Characteristic to be specified
The illumination of the subject which is needed to produce the reference amplitude (100 %) at
the output, either of the green channel signal or the composite video signal with the given iris
setting.
2.1.1.2 Measurement conditions
a) The arrangement for measurement shall be as shown in figure 1.
Light
Neutral density filter Synchronizing
signal
45 °
Video
camera
45 °
Composite video signal
or G channel signal
Test chart
Light
Input terminated by 75 Ω
Signal input
Trigger
input
Input terminated by 75 Ω
Oscilloscope
(--- : use in case of G channel signal)
Underscan
Neither input of the TV monitor is terminated
colour TV monitor
with external
sync input
Figure 1 – Equipment arrangement for measurement of sensitivity
b) The test chart shall be a logarithmic grey scale chart reflective type, see figure 2 (EIAJ
test chart C3 as in annex A of IEC 61146-1, or equivalent). The reflectance of the white area
at the centre is 89,9 %. If the reflectance is other than 89,9 %, see note of 2.1.1.4.
γ equals 2,2 and reflectance of background equals 18 %.
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61146-2 © IEC:1997 – 21 –
0 3 4 56 8
12 7 910
10
h
10 9 8 7 6 54 3 2 1 0
4/3 h
Figure 2 – Specification of grey scale test chart
Step number Reflectance Step number Reflectance
n % n %
0 2,0 6 37,8
1 4,5 7 48,6
2 8,1 8 63,0
3 13,0 9 77,3
4 19,8 10 89,9
5 27,9
c) The camera setting shall be as stated in 1.3.2.3.
2.1.1.3 Method of measurement
a) The G-channel output or luminance output level corresponding to the white part at the
centre is monitored by an oscilloscope. The intensity of illumination shall be so adjusted that
the output level is 714 mV for NTSC cameras or 700 mV for PAL/SECAM cameras. The
level shall be measured from the blanking level. The intensity of illumination may be
adjusted by changing the distance between spotlights and the chart or by inserting neutral
density filters in front of the lens. The density, D, shall be noted when the filters are in use.
Otherwise, D = 0.
b) The intensity, I , of the illumination shall be measured.
0
c) The reference sensitivity in terms of the subject illumination I shall be calculated by the
ref
following equation:
−D
II= 10
0
ref
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61146-2 © IEC:1997 – 23 –
2.1.1.4 Presentation of results
The results of measurement I shall be reported together with the specification of lens as
ref
follows:
subject illumination ___________________ lx (f/5,6);
specification of the lens ________________ .
NOTE – When the reflectance of the white part is other than 89,9 % the actual reflectance R % shall be
measured, and the effective intensity I shall be calculated by the following equation:
0
R
I = I ′
00
89,9
where I′ is the illumination level of the chart.
0
2.1.2 Reference sensitivity (alternative method)
Characteristic to be specified
2.1.2.1
The iris value which is needed to produce the rated amplitude (100 %) at the output, either of
the green channel signal or the composite video signal with the given illumination of the
subject.
2.1.2.2 Measurement conditions
a) The arrangement for measurement shall be as shown in figure 1.
b) The test chart shall be a logarithmic grey scale chart (reflective type, see figure 2) whose
reflectance of the white area at the centre is 89,9 %. If the reflectance is other than 89,9 %,
see note of 2.1.1.4.
c) The illumination of the subject and the camera setting shall be the same as mentioned in
1.3.2.2 and 1.3.2.3 respectively.
2.1.2.3 Method of measurement
a) The G-channel output or luminance output level corresponding to the white part at the
centre is monitored by an oscilloscope. The level shall be measured from the blank
...
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