
Software User’s Manual Ver.A1D-502-V8.03.30-NB
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5-6-5-3 Exposure / White Balance
The section Exposure / White Balance allows the user to configure
Exposure (shutter, iris and gain control) and White Balance settings. In
most cases, the default settings are sufficient and no adjustment is needed. Some options
will only appear under certain Exposure / White balance modes. Each mode is described in
detail below.
White balance refers to the capability of the camera to understand what
“
true white color
is
”
. When the camera knows the true white color, then the rest of the colors will be
accurate, too. While human eye can easily adapt to different lighting sources (even
mixed sources, such as sun light through the window and indoor lights turned on at the
same time), the camera has to understand what is the dominant light source in given
scene and what is the
“
white color
”
of such light source.
By default the camera is in auto white balance mode and attempts to recognize the
light source and its color spectrum automatically and adjusts the image accordingly.
This function works continuously in the background. It is re-evaluated for each frame,
to make sure if there is any change in dominant light source (e.g. the user closes the
curtains to block the sun light and turns on the indoor lights).
In most cases the auto white balance works perfectly and the user does not have to
adjust anything! In some rare installation cases, especially when there are no white
color objects in the field of view, and the light sources are mixed, the camera may have
difficulty to identify the true white color to fine tune the rest of the colors.
In such cases, the installer can
“
help
”
the camera to understand the true colors by
placing a white object (for example a piece of white paper) in front of the camera to
cover the whole field of view and wait a few seconds
–
the auto white balance system
will adjust the colors until the white paper will really look white on the display. At that
moment, the user can freeze these white balance settings by pressing the Hold button.