Axis 2420 Bedienungsanleitung Seite 58

Lenses and Advanced Focusing
58
Exposure Control Overview
The table below provides a summary of the Exposure Control settings in the Image -
Advanced page. Select the parameters for your lens type and product application.
Lens Options
DC-Iris
Non-DC-Iris - Manual
Non-DC-Iris - Shutter
Non-DC-Iris - Auto
Other Advanced Parameters
Lens Options
Shutter Speed
Sharpness
Gain
ALC Level
Description
The DC-Iris setting is the standard factory default setting found on the Image-Advanced page. It allows
the user to manually specify the exposure, shutter speed, gain, and ALC levels.
Choose this setting if you have fitted a non-DC-Iris lens to your AXIS 2420, but wish to adjust the
shutter speed and gain manually.
Choose this setting if you have fitted a non-DC-Iris lens to your AXIS 2420 but wish to adjust the
shutter speed manually.
Choose this setting if you have fitted a non-DC-Iris lens to your AXIS 2420 and would like the shutter
speed and gain to be adjusted automatically.
Description
Derived from the shutter speed on a normal camera, this parameter defines the exposure period for each
image. Use a high shutter speed only if your image subject is expected to be moving quickly; otherwise, a
slower speed will normally suffice.
Defines a level of differentiation between light and dark areas within the image. Corresponding higher lev-
els of sharpness provide for sharper images, but also cause the image compression to be more complex.
Consequently, the file size of a sharp image can be significantly greater than an image that is less sharp.
Adjust the gain to suit the average level of light at your point of installation. The AXIS 2420 should be set to
a corresponding higher level of Gain if your camera is normally monitoring an area at night, or is situated in
a dark room or cupboard.
This defines how acutely the lens reacts to a single light source within the image. For example, with the ALC
level set at a higher level, the headlights from a car will generally cause the calculated average level of light
to increase, and subsequently result in a compensated image that is usually much darker.
Adjusting the ALC to a lower level reduces the sensitivity of the lens to single light sources within the
image.
AXIS 2420 User's Manual