8.Features
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 35
The time width of the flash signal can be got by the following formula:
T
𝑠𝑡𝑟𝑜𝑏𝑒
= T
𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒
Exposure time
Readout time
All lines are exposing at the same time
All lines transfer electrons from
exposure area to storage area
Reading electrons from
storage area line by line
Time
Figure 8-16 Global shutter
⚫
Setting the exposure time
The VEN-U3 series camera supports setting the exposure time, step: 1μs. The exposure time is shown as
follows:
Model
Exposure Mode
Adjustment Range
(μs)
Steps
(μs)
Actual Steps
VEN-161-61U3M-(M01/M05/M06)
Global Shutter
20-1000000
1
1 row period*
Table 8-2 VEN-U3 series camera exposure time setting range
*The exposure precision of the camera is limited by the sensor, when the steps in the user's interface and
the demo display as 1μs, actually the steps are one row period. When the value of the ExposureTime
cannot be divisible by the row period, round up to an integer should be taken, such as the row period is
36us, setting exposure time to 80us, and the actual exposure time is 108us.
When the external light source is sunlight or direct current (DC), the camera has no special requirements
for the exposure time. When the external light source is alternating current (AC), the exposure time must
synchronize with the external light source (under 50Hz light source, the exposure time must be a multiple
of 1/100s, under 60Hz light source, the exposure time must be a multiple of 1/120s), to ensure better image
quality. You can set the exposure time that is synchronized with the external light source by using the demo
or interface function.
The VEN-U3 series camera supports Auto Exposure feature. If the Auto Exposure feature is enabled, the
camera can adjust the exposure time automatically according to the environment brightness. See
