38 Pelco Manual C1456M-D (10/98)5.11.5 Gain/AGC5.11.5.1 AGC Mode
There are three AGC (Automatic Gain Control) modes: auto, on, and off.
In the auto mode, the Spectra® (Version 3.0) dome automatically adjusts the gain
- the amount of amplification the camera places on its video information in order
to obtain a full 1-volt peak-to-peak video signal out. If the iris is manually opened
to its wide-open position and the picture is weak, the AGC can be turned off and
the gain increased manually to improve the picture. For instructions on how to do
this, refer to Section 5.11.6, AUTO IRIS. When you close the iris, the AGC will
turn back on automatically when the lens iris starts closing.
In the on mode the AGC is on all the time.
In the off mode the AGC is off.
To change the AGC mode:
1. Program preset 95 (28 if in 32-preset mode; refer to Section 5.4, PRESET
FUNCTIONS) to access the main menu (refer to Section 5.11.1, MAIN MENU
ACCESS). The main menu will appear.
2. If the cursor (>) is not beside Camera, move the joystick up or down to position
the cursor beside Camera.
3. Press the Iris Open button to enter the Camera submenu.
4. Move the joystick up or down to position the cursor beside Gain/AGC.
5. Press the Iris Open button to enter the Gain/AGC submenu.
6. Move the joystick up or down to position the cursor beside AGC mode.
7. Press the Iris Open button on your keyboard. A star will appear beside AGC
mode and the cursor will move to the right beside the word Auto, On, or Off.
8. Move the joystick up or down to position the cursor beside Auto, On, or Off.
9. SELECT - Press the Iris Open button on your keyboard to select your choice.
CANCEL - Press the Iris Close button if you do not want to change the setting.
5.11.5.2 Gain
The gain adjusts the signal level of the video output. Increasing the gain in low light
conditions will increase the level of noise in the picture.
To change the gain:
1. Program preset 95 (28 if in 32-preset mode; refer to Section 5.4, PRESET
FUNCTIONS) to access the main menu (refer to Section 5.11.1, MAIN MENU
ACCESS). The main menu will appear.
2. If the cursor (>) is not beside Camera, move the joystick up or down to position
the cursor beside Camera.
3. Press the Iris Open button to enter the Camera submenu.
4. Move the joystick up or down to position the cursor beside Gain/AGC.
5. Press the Iris Open button to enter the Gain/AGC submenu.
6. Move the joystick up or down to position the cursor beside Gain.
7. Press the Iris Open button on your keyboard. A star will appear beside Gain and
the cursor will move to the right beside the current gain setting (a numeric value).
8. Move the joystick up or down to change the gain. As you change the gain, the
picture on your monitor will get brighter or darker.
9. SELECT - Press the Iris Open button on your keyboard to select your choice.
CANCEL - Press the Iris Close button if you do not want to change the setting.