16
3.1
Functions
When installing a camera, it is important to adjust the settings to match normal operating conditions (indoor, outdoor and/or
night-time). Results can be improved by adjusting several settings at once.
With more sophisticated models (EFFIO P) difficult light conditions, such as backlight, can be managed more effectively.
The following settings typically have an impact on picture quality. They have been discussed and grouped on the basis of the
conditions affecting the camera's surroundings.
3.2
Luminosity Management: matching the environment (indoor, outdoor or night-time).
3.2.1
Picture Adjustment:
-
"PICT ADJUST"
"Brightness", "Contrast", "Sharpness", "Hue", "Gain".
-
"SHUTTER/AGC"
combines:
o
"SHUTTER": shutter speed
o
"IRIS": opening the lens diaphragm
Adjusting both the shutter and the iris determines how much light reaches the sensor over a given time period.
o
"AGC" (Auto Gain Control): the "GAIN" is the signal amplification
-
"WHITE BALANCE"
: facilitates sensor calibration and correction of colour cast to suit the ambient lighting. Different
types of light contain specific colour casts: for indoor lighting (tungsten) this is more orange-coloured, while for daylight
it tends to be blue; under cloudy skies it is whitish, and under neon lights it is greenish. This is referred to as colour
temperature. The human eye is not confused by colour temperature differences, but cameras need to be "calibrated" in
order for their video colorimetry to be accurate. The white balance can be adjusted manually using "MANUAL WB" or,
alternatively, automatic adjustment options can be used, e.g.:
o
"ATW"
(Auto Tracing White Balance): the camera automatically adjusts the white balance in response to
changes in light. The "ATW FRAME" setting determines how often readjustments are made.
Further controls found in this menu ("SPEED", "DELAY CONT", "ATW FRAME") can be used in environments where
different kinds of lighting, such as fluorescent tubes, sunlight and incandescent light, occur in combination.
o
"ANTI-CR (Anti Colour Rolling)": if the camera is installed in a location lit by a fluorescent light source, it can be
affected by the flicker rate of the light source, causing the white balance to alter the colours on a cyclical basis.
This undesirable effect is known as "Colour Rolling" and "Anti CR" is the function designed to eradicate it.
o
"INDOOR", "OUTDOOR": All cameras can have their white balance mode pre-set to suit a predefined
environment.
3.2.2
Enhanced Visualisation of Dark/Night-time Images: "AGC (Auto Gain Control)", "NR (Noise Reduction)",
"HLC (High Light Compensation)".
The electronic circuit takes real-time measurements of the light levels being picked up by the camera. If they fall below the
operating threshold for colour mode, the surveillance camera automatically switches to black and white mode. The minimum
light level required is only 0.1 Lux for colour and 0.01 Lux for black and white.
-
"AGC"
(Auto Gain Control): measures the strength of the video signal in real time, then, if the signal is too weak (the
picture is too dark), amplifies it. This function means that pictures can automatically be brightened when the surveillance
camera is located in an environment with insufficient lighting. Excessive gain generates image noise.
menu "SHUTTER/AGC"
-
"DAY/NIGHT"
: pre-sets the levels at which the camera switches from day to night/night to day in "AUTO" mode, or sets
the camera permanently to black & white or colour.
