Axis Q1635 User Manual page 26

AXIS Q1635 Fixed Network Camera
Video and Audio
Exposure control - This setting is used to adapt to the amount of light used. Automatic is the default setting and can be used in
most situations. The shutter speed is automatically set to produce optimum image quality. Flicker-free 50 or 60 Hz is used to remove
flicker which can be caused by fluorescent and other light sources. The Hold current option locks the current exposure settings.
Enable Backlight compensation - Enable this option if a bright spot of light, for example a light bulb, causes other areas in
the image to appear too dark.
Exposure zones - This setting determines which part of the image is used to calculate the exposure. For most situations, the Auto
setting can be used. For particular requirements, select a predefined area.
Exposure priority - When Motion is prioritized and maximum Shutter time is set to a small value, motion blur in the image is
minimized. This can be useful for recognition of moving objects such as people and vehicles. However, prioritizing motion may cause
an increase in image noise, especially in low light situations. When Low noise is prioritized and Gain is set to a small value, image
noise is minimized. The file size is reduced, which can be useful if storage space or bandwidth is limited. However, prioritizing low
noise may result in a very dark image, especially in low light situations.
Shutter & Gain
The shutter and gain settings affect the amount of motion blur and noise in the image. To adapt to different lighting, available
storage space and bandwidth, it is often necessary to prioritize either low motion blur or low noise. The Axis product allows
using different prioritization in normal light and in low light.
Shutter speed is related to the amount of time the shutter is opened and is measured in seconds (s). A slow shutter speed allows
more light to reach the sensor and can help produce a brighter image in low light situations. On the other hand, a slow shutter
speed can cause moving objects to appear blurry.
Set Shutter to
• Auto to set the shutter speed automatically. If required, use Max shutter to limit the shutter speed to prevent the frame
rate from being reduced.
• Fixed to use a fixed shutter speed.
Gain, measured in decibel (dB), is the amount of amplification applied to the image. A high gain may provide a better image in low
light situations but will increase the amount of image noise.
Set Gain to
• Auto to set the gain automatically. If required, use Max gain to limit the applied gain.
• Fixed to use a fixed gain.
When Shutter and Gain are both set to Auto, it is possible to set the Priority between low motion blur and low noise manually and to
use a different Priority in Normal Light and in Low Light.
Example
Consider an area where people or vehicles move during the day, but where there should be no movements during night. To be able to,
for example, recognize faces or license plates, move the normal light priority slider toward low motion blur. At nighttime, motion
detection is more important than identification. Motion blur is acceptable and since low light can cause a lot of noise, move
the low light priority slider toward low noise.
Example
If storage space or bandwidth is limited, try using a lower gain. This will reduce image noise and produce smaller image files.
Iris configuration
Iris configuration shows the current configured iris type. Do not change the iris configuration unless the lens has been changed, see
Replace the Lens on page 10.
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