User manual

There are two types of variable focus lenses:
 Varifocal lenses, which can increase or decrease the focal length but need to be refocused
after each adjustment.
 Zoom lenses, which remain in focus during changes to the focal length.
8.5 Lens Mounts
Each lens requires a specific mounting assembly that places the lens a certain distance from the
camera’s imaging chip. If the lens is not placed at the proper distance, it will not be possible to
focus the lens. C-mount lenses require 5mm greater distance from the imaging chip than CS-
mount lenses. The cameras have a built-in mount for CS-mount lenses. A “C” mount adapter is
also included to accommodate C-mount and micro-mount lenses.
8.6 Depth of Field
Depth of field is the area of a scene that is in sharp focus. When only one portion of the scene is
in sharp focus, it is called shallow depth of field. When a lens has a shallow depth of field, only
objects located in close proximity to one another at a certain distance from the camera will be in
focus, while other objects that are closer to the camera or farther away will be out of focus. A
large depth of field means that a high percentage of the image is in focus, including objects that
are close to the camera and those that are far away from it. Two factors determine a camera s
depth of field: the aperture of the lens and the focal length of the camera s lens. Generally,
smaller lens openings increase the depth of field. As the camera’s iris becomes more open, letting
more light into the camera, the depth of field will decrease. Wide-angle lenses have a greater
depth of field than telephoto lenses.
8.7 Iris (aperture)
The iris controls the amount of light that enters the camera. In poorly lit situations, the iris should
be almost fully open. In well-lit scenes, the iris can be closed almost completely. The iris setting
directly affects the depth of field. Consider the percentage of the image that needs to be in sharp
focus before adjusting the iris setting.
Note: The camera can account for a large variation in admitted light. However, too
much light can cause the camera to lose contrast. Too little light can cause motion
blur.
Small iris openings greatly increase your depth of field. However, since the camera needs a
longer exposure time to capture more light when the iris opening is small, motion blur may be
experienced when the camera has a small iris opening.
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