Basler A640F, Руководство пользователя

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Basic Operation & Standard Features
BASLER A640
f
3-3
DRAFT
3.2 Exposure Control
3.2.1 Setting the Exposure Time
Exposure time is determined by a combination of two values. The first is the setting in the Value
field of the Shutter control register (see page
4-30 ). The second is the Shutter Time Base.
Exposure time is determined by the product of these two values:
Exposure Time = (Shutter Value Setting) x (Shutter Time Base)
The shutter time base is fixed at 20 µs by default. Exposure time is normally adjusted by changing
the setting in the Value field of the Shutter control register. The shutter value setting can range
from 1 to 4095 (0x001 to 0xFFF). So if the Value field of the Shutter register is set to 100 (0x064),
for example, the exposure time will be 100 x 20 µs or 2000 µs.
As mentioned above, the shutter time base is normally fixed at 20 µs and the exposure time is
normally adjusted by changing the shutter value setting. However, if you require an exposure time
that is shorter or longer than what you can achieve by changing the shutter value alone, the
shutter time base can also be changed. The Shutter Time Base smart feature can be used to
change the shutter time base. For more information on changing the shutter time base, see
Section
6.7.13 .
3.2.2 Maximum Exposure Time
The maximum exposure time for a given frame rate is determined by the following formula:
For example, if a camera is operating at 11 fps:
So in this case, the maximum exposure time is 90.9 ms.
L
Exceeding the maximum exposure time for your frame rate will cause the camera to
slow down, i.e., it will cause the camera to operate at a lower frame rate.
1
frame rate
--------------------------- maximum exposure time =
1
11 fps
---------------- 0.0909 s =