Video gain selection

The gain can be raised to enable images in locations with inadequate lighting. Notice that noise increases as the gain is raised.

1.The viewfinder image darkens when lighting is insufficient. If the lens is auto iris, the iris opens completely. The iris setting can be checked from the viewfinder screen.

2.When the gain switch is set to M or H, an exclamation point (!) appears in the viewfinder to advise of high gain mode.

L:standard (normal) gain (0, -3dB)

M:(6, 9, 12dB)

H:(12, 18, 24dB)

3.Gain values at L, M and H switch positions are set at the Function 1 page.

FUNCTION 1

SCENE 1

CONTRAST

:OFF

AUTO IRIS

:AVERAGE

GAIN LOW

:0dB

MID

:9dB

HIGH

:18dB

DTL

:->

MASKING

:PRESET

GAMMA

:PRESET

INITIALIZE

 

 

 

GAIN switch

Gain value

 

-3dB

 

 

 

 

L(LOW)

0dB

 

 

 

 

 

 

 

 

 

 

 

 

 

M(MID)

6dB,

9dB

, 12dB

 

 

 

 

 

 

 

 

 

 

 

H(HIGH)

12dB,

18dB

, 24dB

 

 

 

 

 

 

 

4.ULTRA GAIN

When the gain setting is above +12 dB, set the Ultra Gain switch to on to increase the sensitivity about 12 dB further. Notice this reduces the horizontal resolution by about half. Normally set the switch to off.

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Hitachi V-21W operating instructions Video gain selection, Llow, Mmid, Hhigh, Ultra Gain