Monday, July 19, 2010

Explanation Of Lens Size In Security Cameras

Security Camera


Security camera lens size determines how wide a field of view a camera will have, as well as the details the camera will pick up. Lens size is critical when determining if a camera will perform as needed.


Wide Angle


To cover a large area, the lens needs to have a wide field of view. This would be considered a wide-angle lens. However, a wide-angle lens will not allow you to pick up much detail, such as a license plate number or the details of a person's face.


Telephoto


A telephoto lens will allow you to see details, but the field of view will be very narrow.








Millimeters


Lenses sizes are measured in millimeters (mm). Lower mm lenses are wide angle lenses, and high mm lenses are telephoto lenses.


CCD


The CCD (charged coupled device) is what allows the camera to pick up an image; it is like the retina of the camera. The size of the CCD must be taken into account when determining the correct lens size.


Calculator


To understand exactly how lens size affects what a camera will see, you must know the CCD size and use a lens calculator. Roughly estimated, a 2.8 to 4 mm lens is considered wide angle, and 12 mm and higher would be considered a telephoto lens.

Tags: camera will, field view, lens size, lens will, lens will allow