ALLIED Vision Technologies Guppy PRO F-503 - Manual (Page 157)

Controlling image capture
Guppy PRO Technical Manual V4.0.0
155
Example: Guppy PRO F-031
register value x time base + exposure time offset = exposure time
100 x 20 µs + 71 µs = 2075 µs exposure time
The minimum adjustable exposure time set by register is 4 µs.  The real
minimum exposure time of Guppy PRO F-031 is then:

4 µs + 71 µs = 75 µs
Extended shutter
The exposure time for long-term integration of
• up to 67 seconds for the CCD models
• up to 22 seconds for the Guppy PRO F-503 (CMOS model)
can be extended via the advanced register: EXTENDED_SHUTTER
The longest exposure time, 3FFFFFFh, corresponds to 67.11 sec.
The lowest possible value of ExpTime is camera-specific (see Table 62: Cam-
era-specific minimum exposure time on page 154).
Camera Register value Time base (default)
Guppy PRO F-031 100 20 µs
Table 63: Register value and time base for Guppy PRO F-031
Register Name Field Bit Description
0xF100020C EXTD_SHUTTER Presence_Inq [0] Indicates presence of this feature (read
only)
--- [1.. 5] Reserved
ExpTime [6..31] Exposure time in µs
Table 64: Advanced register: Extended shutter
Note

• Exposure times entered via the 81Ch register are mir-
rored in the extended register, but not vice versa.
• Longer integration times not only increase sensitivity,
but may also increase some unwanted effects such as
noise and pixel-to-pixel non-uniformity. Depending on
the application, these effects may limit the longest
usable integration time.
• Changes in this register have immediate effect, even
when the camera is transmitting.
• Extended shutter becomes inactive after writing to a
format/mode/frame rate register.