Pelco C2404M-A (4/05) , AGC (AUTOMATIC GAIN CONTROL), VARIFOCAL LENS AUTO IRIS LEVEL ADJUSTMENT, How to Adjust the Phase Control, VERTICAL PHASE ADJUSTMENT (24 VAC OPERATION ONLY), BLC (BACK LIGHT COMPENSATION),

C2404M-A (4/05) 11
AGC (AUTOMATIC GAIN CONTROL)
AGC automatically adjusts the image to compensate for changes in light levels.
ON (Default setting) – Enables the AGC mode.
OFF – Disables the AGC mode.
BLC (BACK LIGHT COMPENSATION)
The BLC (backlight compensation) feature compensates for backlit scenes by enhancing objects in the
center of the scene.
OFF (Default setting) – Disables the BLC mode.
ON – Enables the BLC mode. Use this setting if a bright backlight is present and the subject in the
center of the picture appears dark or as a silhouette.
VERTICAL PHASE ADJUSTMENT (24 VAC OPERATION ONLY)
When using more than one camera power supply, a brief vertical roll may occur on the monitor when
a camera view is switched. To eliminate vertical roll reverse the 24 VAC connections on one camera.
If both cameras are connected to the same transformer, this should solve the problem. If reversing the
connections does not solve the problem, adjust the phase control by synchronizing, or line-locking, the
cameras to one another.
How to Adjust the Phase Control
It may be necessary to have two people in communication when synchronizing the cameras: one
person at the camera and another person at the monitor to observe the vertical roll and the effect of
any adjustments made at the camera.
To synchronize the cameras:
1. Choose a reference camera to which all other cameras will be phased.
2. Select a camera and synchronize it to the reference camera by turning the phase adjustment
control clockwise and/or counterclockwise.
3. Each time an adjustment is made, switch back and forth between the camera you are
adjusting and the reference camera. Repeat this process as many times as necessary, until the
roll between the cameras is no longer noticeable.
4. Adjust the phase of all other cameras by repeating steps 2 through 3. Always adjust to the
reference camera selected in step 1.
VARIFOCAL LENS AUTO IRIS LEVEL ADJUSTMENT
To adjust the auto iris level, turn the level adjustment counterclockwise to decrease the brightness
level and clockwise to increase the brightness level.
NOTE: The preferred method for camera phase adjustment is to use a dual trace oscilloscope
to align the vertical synchronization pulses of the reference camera to the selected camera(s).
C2404M-A.book Page 11 Monday, April 18, 2005 9:11 AM