Our experience has shown that one of the most confusing aspects of selecting CCTV equipment is in the selection of the lens. This technical note is designed to help anyone select the proper lens for a CCTV application. First the good news. All of the cameras and lenses listed on our site are designed for complete compatibility. There is no incorrect pairing possible using the cameras and lenses listed in the product sections of the store. All of our lenses are color corrected, meaning that the lenses will work on color or black and white cameras. Some of the basics in lens selection are as follows; lenses with a manual iris are best used for indoor applications, and lenses with an auto iris are best used for outdoor applications. A manual iris lens has a ring that can be adjusted to let more or less light in. With an auto iris lens, a cable is plugged into the camera that allows the camera to control how much light is allowed into the camera. This allows the camera/lens combination to react to changes in light. Lenses also are selected based on the focal length. The focal length of a lens determines how wide the picture will appear on the monitor. Lenses with a lower focal length will give a wider picture on the monitor. Generally with most 1/3" format cameras our customers prefers using either 4mm lenses for a wide picture, and 8mm lenses for a more narrow picture. If you are unsure of the exact picture that you are looking to view, then consider using a "vari-focal lens". The lenses are avaialbe in the lens section of our website, and they allow you to field adjust the lens from a range of 3.5mm (wide) to 8mm (narrow). You can find manual iris varifocal lenses fo indoor use, as well as auto iris varifocal lenses for outdoor use. For more complex systems, you can add a motorized zoom lens which will allow you to remotely control the focal range of the lens, and zoom in or out, similar to a camcorder. For more complex installations, please don't hesitate to contact our technical sales department at sales@ccve.com. We look forward to helping you! |
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