Basic Operation and Features
Basler A400k
3-9
DRAFT
3.4.1 Guidelines for Successful Use of the Rolling Shutter
To successfully use the rolling shutter functionality of the camera, make sure that you observe the
guidelines listed below.
• Exposure time can only be set incrementally in multiples of 4.56 µs. Formula:
where N must be an integer and > 0. Exposure time can range from 4.56 µs to 19.12 s.
• The runtime of the sensor reset and readout depends on the height of the area of interest
(AOI, see page
). The formula below can be used to calculate the runtime:
Reset runtime = Readout runtime = 4.56 µs x (AOI Height - 1)
• The formula below can be used to calculate the total time it takes to reset, expose and read
out a single frame:
Examples:
(A) The height of the area of interest (AOI) is 1726 lines (full resolution):
Total runtime = 4.56 µs x (1726 - 1) + Exposure time = 7866 µs + Exposure time
(B) The height of the area of interest (AOI) is only 200 lines:
Total runtime = 4.56 µs x (200 - 1) + Exposure time = 907.4 µs + Exposure time
• Imaging of fast moving objects requires a flash exposure within the camera’s flash window
3.4.2 Flash Exposure for Fast Moving Objects
Imaging of fast moving objects requires a flash exposure. If flash exposure is not used, image
distortions will occur due to the exposure’s 4.56 µs offset from one line to the next.
Due to the exposure’s 4.56 µs offset from one line to the next, there is a limited time interval where
all pixel lines are open, that is, all pixels are exposed to light simultaneously. This time interval is
called the “flash window“ of the camera (see
).
The flash window opens when exposure is started in the last pixel line within the area of interest
(AOI) and it closes when readout is started in the first pixel line within the AOI. The width of the
flash window is calculated using the below formula:
Flash window width [µs] = Exposure time [µs] - (AOI Height x 4.56 µs)
A400k cameras output a flash trigger signal that can be used to trigger flash exposure. The flash
trigger signal can be programmed to be high as long as the flash window is open, that is, all pixel
lines are exposed to light and the flash should occur (see Section
on page 2-32).
Exposure time
N
4.56
μ
s
×
=
Total frame exposure runtime
4.56
μ
s
AOI Height
1
–
(
)
Exposure time
+
×
=
Summary of Contents for A400K
Page 1: ...Basler A400k USER S MANUAL Document Number DA00062410 Release Date 27 September 2007 ...
Page 4: ......
Page 25: ...Camera Interface Basler A400k 2 9 DRAFT Figure 2 5 A402k Camera Frame Grabber Interface ...
Page 26: ...Camera Interface 2 10 Basler A400k DRAFT Figure 2 6 A403k Camera Frame Grabber Interface ...
Page 27: ...Camera Interface Basler A400k 2 11 DRAFT Figure 2 7 A404k Camera Frame Grabber Interface ...
Page 52: ...Camera Interface 2 36 Basler A400k DRAFT ...
Page 154: ...Configuring the Camera 4 54 Basler A400k DRAFT ...
Page 168: ...Troubleshooting 6 10 Basler A400k DRAFT ...
Page 172: ...Feedback iv Basler A400k DRAFT ...
Page 176: ...Index viii Basler A400k DRAFT ...