VIVOTEK
User's Manual - 71
The inclusive window refers to the “weighed window“; the exclusive window refers to the “ignored
window.“ It adopts the weighed averages method to calculate the value. The inclusive windows have
a higher priority. You can overlap these windows, and, if you place an exclusive window within a larger
inclusive window, the exclusive part of the overlapped windows will be deducted from the inclusive
window. An exposure value will then be calculated out of the remaining of the inclusive window.
■
BLC
(Back Light Compensation): This option will automatically add a “weighted region“ in the middle of
the window and give the necessary light compensation.
Include
Exclude
Weighted region
Ignored region
Include
Exclude
■
Exposure time: you can split the round pointers on the
Exposure time
and
Gain control
slide bars
into two halves and drag them on the bars to designate a range of values in which firmware can
automatically adapt to. Note that Firmware will then automatically tune the Gain, Exposure time, and
Iris opening within the ranges you specified. For example, in low-light condition, you may prefer a
longer exposure time and more electronic gains. However, the noises in the image will also increase.
■
Flickerless:
Under some circumstances when there is a difference between the video capture
frequency and local AC power frequency (NTSC or PAL), the mismatch causes color shifts or flickering
images. If the above mismatch occurs, select the
Flickerless
checkbox, and the range of Exposure
time (the shutter time) will be limited to a range in order to match the AC power frequency. When
selected, the exposure time will be forced to stay longer than 1/120 second. For cameras that come
with fixed iris lens, setting the exposure time to longer than 1/120 second may introduce too much
lights to the lens. Users can use this option to observe whether the result of long exposure time is
satisfactory.
You can click and drag the semi-circular pointers on the
Exposure time
and
Gain control
slide bars
to specify a range of shutter time and Gain control values within which the camera can automaticallly
tune to an optimal imaging result. For example, you may prefer a shorter shutter time to better capture
moving objects, while a faster shutter reduces light and needs to be compensated by electrical
brightness gains.
■
HLC
: (Highlight Compensation). Firmware detects strong light sources and compensates on affected
spots to enhance the overall image quality. For example, the HLC helps reduce the glares produced by
spotlights or headlights.
Exposure control:
■
Exposure level: You can manually set the Exposure level, which ranges from -0.7 to +0.7 (dark to
bright).
