IEC 61146-4:1998 pdf download.Video cameras (PAL/SECAM/NTSC) – Methods of measurement – Part 4: Automatic functions of video cameras and camera-recorders
1 Scope
This part of IEC 61 1 46 applies to the assessment of characteristics of automatic functions which are implemented in colour video cameras and camera-recorders. The performance to be assessed in this standard is limited to automatic functions relating to light input from the lens and to the electronic output from video cameras and the video camera portions of camera- recorders. This standard defines test patterns, measurement conditions, methods of measurement and the presentation of measured results so as to make possible the comparison of the measurement results. This standard intends to provide an objective method of measurement for each characteristic of the automatic functions but the results of objective measurements may not correlate well with the subjective assessment of automatic functions. It does not specify limiting values for the various characteristics related to automatic functions.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61 1 46. 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 61 1 46 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 61 1 46-1 :1 994, Video cameras (PAL/SECAM/NTSC) – Methods of measurement – Part 1 :
Non-broadcast single-sensor cameras
ISO 8341 :1 989, Photography – Slide projectors and filmstrip projectors – Illumination test
3 Terms and definitions
For the purpose of this part of IEC 61 1 46, the following definitions apply.
3.1 grey scale chart
test chart which has logarithmic grey steps of = 2,2 specified in item 1 of annex A of
IEC 61 1 46-1
3.2 tracking chart
test chart with a radial arrangement of black and white wedges (see annex A)
3.3 resolution chart
test chart specified in item 4 of annex A of IEC 61 1 46-1
3.4 uniform white chart
test chart specified in item 2 of annex A of IEC 61 1 46-1
3.5 equipment under test
colour video camera and camera-recorder with electronic output(s)
4 Conditions
4.1 Environmental conditions
All measurements shall be carried out within the environmental conditions as specified by the
manufacturer.
The environmental conditions during measurement, at least the temperature and the relative
humidity, shall be reported together with the presentation of the measurement results.
4.2 Conditions of measurement
4.2.1 Illumination
a) The illumination of test charts should be performed by two or four spot lights depending on
the characteristics to be measured.
b) The correlated colour temperature of the spot light shall be 3 1 00 K 1 00 K.
c) Unless otherwise specified, the illumination level of the test chart shall be 2 000 lx 1 00 lx.
d) The non-uniformity of the illumination shall be less than 5 %.
e) The methods used for all the measurements shall be in line with the standard methods
specified in ISO 8341 .
4.2.2 Shooting conditions
a) An optical axis of the equipment under test shall coincide with a normal line of the test
chart.
b) Unless otherwise specified, the distance between the test chart and the equipment under
test should be approximately 2 m.
c) Unless otherwise specified, the zooming should be adjusted so that horizontal and vertical
markers just fit the full frame of an under-scan monitor.
4.2.4 Reliability of measured results
The reliability and repeatability of measured results may be affected by the automation
processes incorporated in the equipment under measurement. Some automatic functions may
exhibit instability. Therefore, averaging of data obtained by multiple measurement may be
necessary if additional precision is required.
5 Method of measurement of automatic functions
5.1 Automatic exposure control
5.1.1 Dependency on illumination level
5.1.1.1 Characteristics to be measured
Dependency of absolute luminance signal levels and their relative deviation on illumination level.
5.1.1.2 Measurement conditions
The measurements shall be conducted using the grey scale chart of = 2,2. The equipment
arrangement shall be as shown in figure 1 .
IEC 61146-4:1998 pdf download
