Sony ISSUE 3 Camcorder User Manual


 
Another characteristic of lenses is the ‘depth of field’ (see illustration). If a lens is
focused on an object there will be a certain area of sharp focus in front of and
behind the object. The depth of this area of sharp focus is controlled by three
factors: the focal length of the lens, the distance from the lens to the object
and the F stop.
Lens Format
The lens format relates to the camera format, 1/3 inch, 1/2 inch, 2/3 inch.
There are two lens mounting systems. Most CCTV cameras have a ‘C’ mount,
although many now use a ‘CS’ mount.‘C’ mount cameras are not able to use ‘CS’
lenses, however adaptors are available.
To avoid the complexities of lenses with automatic irises, manufacturers have
developed ‘electronic shutters’. These achieve the same light adjustment with
simpler, fixed iris lenses.The CCD iris common to most Sony CCTV cameras
automatically controls image exposure by electronically adjusting the incoming
light levels.
Cameras with Built-in Lens
Some cameras are now available with a built-in lens. Sony manufactures a 1/3 inch
colour camera with an integral 5.4mm - 64.8mm zoom lens (SSC-CX34P) which
can be used in place of the conventional camera and motorised lens set-up. This
saves installation time and the resultant set-up is lighter, allowing the use of more
compact camera housing and pan and tilt head.
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For more information contact the Sony Business Information Centre: 01932 816340
Selecting the Correct Lens