User Manual

Controlling image capture

Guppy PRO Technical Manual V4.0.0

155

Example: Guppy PRO F-031

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

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.