Axis Communications 2120 user manual Exposure Control Overview, Other Advanced Parameters

AXIS 2120 User’s Manual Adjusting the Camera Focus 43

Exposure Control Overview

The table below provides a summary of the Exposure Control settings in the Image - Advanced page. Select the parameters appropriate to your lens type and product application:

Lens Options	Description
DC Iris	The AXIS 2120 is supplied with a DC Iris lens as standard; consequently, the DC Iris setting is the
	standard factory default setting within the Image-Advanced page. It allows the user to manually
	specify the exposure, shutter speed, gain, and ALC levels.
Non DC Iris - Manual	Choose this setting if you have fitted a non-DC Iris lens to your AXIS 2120, but wish to adjust the
	shutter speed and gain manually.
Non DC Iris - Shutter	Choose this setting if you have fitted a non-DC Iris lens to your AXIS 2120, but wish to adjust the
	shutter speed,manually.
Non DC Iris - Auto	Choose this setting if you have fitted a non-DC Iris lens to your AXIS 2120 and would like the shutter
	speed and gain to be adjusted automatically.

Other Advanced Parameters

Lens Options	Description
Shutter Speed	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.
Sharpness	Defines a level of differentiation between light and dark areas in the image. Corresponding higher
	levels 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 for an image
	that is less sharp.
Gain	Adjust the gain to suit the average level of light at your point of installation. The AXIS 2120 should
	be set to a corresponding higher level of Gain if your camera is normally monitoring an area at
	night, or is sited in a dark room or cupboard.
ALC Level	This defines how acutely the lens reacts to a single light source within the image. For example, with
	the ALC level set to a lower level, the headlights from a car will generally cause the calculated aver-
	age level of light to increase, and subsequently result in a compensated image that is usually much
	darker.
	Adjusting the ALC to a higher level reduces the sensitivity of the lens to single light sources within
	the image.