User manual

VIVOTEK
56 - User's Manual
Exposure control:
■
Exposure level: You can manually set the Exposure level, which ranges from -2.0 to +2.0 (dark
to bright). 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 automatically tune to an optimal imaging result. 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.
■
Exposure mode:
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. You can also configure the iris size to control
the amount of light. 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.
The inclusive window refers to the “weighed window“; the exclusive window refers to “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
- Flickerless:
Fixed iris models can encounter image rolling band issues when
operating under incongrous
power line frequency with uorescent lights. To solve the problem, the Flickerless mode can limit
the exposure time to 1/120 ~ 1/5 second. For the Auto iris models, when the exposure time is
limited to 1/120 ~1/5 second, iris size is automatically adjusted, and that the image brightness
is appropriately adjusted. Although the chance is rare, for Fixed iris models, when the exposure
time is limited to 1/120 ~ 1/5 second, they may encounter image over-exposure. If the Flickerless
option is selected, and users discover over-exposure from the live view, they can disable the
Flickerless option.