BOBCAT HD-SDI
Hardware User’s Manual
Imperx, Inc.
Rev. 1.4
6421 Congress Ave.
6/2/2014
Boca Raton, FL 33487
+1 (561) 989-0006
45 of 175
2.4.3.
Automatic Exposure Control (AEC)
The camera can be set to automatic exposure (and gain) control in order to
keep the same image brightness during changing light conditions. Both modes
– automatic exposure and automatic gain can be enabled simultaneously. In
this mode the user sets the image brightness (luminance) to be maintained, and
the camera adjusts the exposure accordingly. The user can select the average or
peak brightness to be maintained. The camera starts with changing the
exposure within the preset by the user min-max limits. If one of the exposure
limits has been reached, the camera indicates the limit has been reached and
keeps the value until the light condition change. The speed of convergence
(how fast the camera stabilizes after change), can be preset by the user (four
possible options are available). The AEC algorithm samples all pixels for the
entire frame, but the user can select only a portion of the image (AOI) to be
used as a sample collecting region. The camera displays the current luminance,
current exposure and current gain. For auto gain control refer to Automatic
Gain Control (AGC) section.
CAUTION NOTE
1. In some bright light conditions a very small exposure values (~
microseconds) must be used. In such cases the camera response is not linear,
i.e. equal exposure increments do not result in equal brightness increase. In
some rare occasions during such conditions, an image brightness oscillation
(image flipping from bright to dark) could occur. To prevent this, please
change the AEC/AGC setting (exposure speed, luminance level or AOI), or
change the lens iris.
2.4.4.
Automatic Iris Control (AIC)
The camera has a built in auto iris control feature, which is hardware
compatible with a "Video” auto iris lens. If enabled, the camera provides an
analog video signal (via 12 pin HIROSE connector), which is used by the lens
to control the iris.
2.5.
STROBE OUTPUT
The strobe output is used to synchronize an external light source with the camera
timing, and thus to maximize the camera efficiency in low light level conditions. The
optimal strobe signal position is achieved by the positioning of the STROBE pulse,
with respect to the vertical transfer pulse VCCD (end of the frame) - Figure 2.7.
BOBCAT supports two independent strobe signals. Each strobe pulse can be
positioned within the entire frame timing period with a precision 1.0 us. The strobe
duration can be seen from 1.0 us to 65535 us with a precision of 1.0us. The internal