User’s Manual
23
3.3.5 AE MODE
The exposure is the amount of light captured by the image sensor and is determined
by how wide you open the lens diaphragm (iris adjustment), how long you leave the
sensor exposed (shutter speed) and other exposure parameters. This option allows
users to define how the Auto Exposure (AE) function will work.
18×/26× Model:
• AUTO
In this mode, the camera’s IRIS and AGC (Auto Gain Control) circuits work
together automatically to adjust the light exposure of the image sensor in
order to obtain a consistent video output level. In these conditions, the shutter
speed is fixed at 1/60 (NTSC) or 1/50 (PAL). Users can adjust the internal
brightness reference level using auto exposure compensation to control the
brightness of camera. The exposure compensation value can be selected
between <0> and <16> and the gain varies from -10.5 dB to 10.5 dB. Each
step is 1.5 dB and an exposure compensation value of <7> is equal to a gain
value of 0 dB. The camera will not compensate for brightness if exposure
compensation is set to <OFF>. The default setting is <OFF>.
• BRIGHT
The brightness control function adjusts the IRIS and AGC gain using an
internal algorithm. The brightness is controlled by the gain in dark lighting
conditions and by the iris in bright lighting conditions.
• SHUTTER
This option means that the shutter speed is the main factor controlling the
exposure, and both IRIS and AGC will function automatically in conjunction
with the set shutter speed to achieve consistent exposure output.
• GAIN
The automatic gain control function means that the gain is the main factor
controlling the exposure, taking priority over SHUTTER and IRIS. The
internal circuit will function automatically to obtain a consistent exposure.
• IRIS
This option gives the IRIS function a higher priority. The shutter speed and the
AGC circuit will function automatically in conjunction with the ARIS setting to
obtain consistent exposure output. Opening a lens controls the amount of light
reaching the surface of the selected device. Increasing the F-stop number
(F/1.6, F/2, F/2.4, etc.) allows less light to pass.