What is a Security Camera Lens?
A security camera lens is the round disc of glass that light must pass through to hit the image sensor. The shape of the lens, and its distance from the image sensor, will determine what type of view your camera has—normal (what our eyes can see), telephoto (small field of view to see small details), or wide angled (larger field of view with less detail).
How a Security Camera Lens Works
When light hits the camera lens, it is channeled back onto the image sensor which records what light hits the pixels to capture an image. Which type of lens you want in your camera depends on what the camera is recording.
For surveillance cameras, there are three types of lenses:
- Fixed, so the lens cannot move to change the field of view or focal length
- Varifocal, where the lens is adjustable so you can adapt it to different focal lengths, although you will also need to refocus the camera after adjusting it
- Zoom, which is similar to a varifocal lens in that the lens can move to different focal lengths but it will maintain focus while moving
A fixed lens would work well in an area with objects that are a consistent distance away from the camera, say while monitoring the entrance to a room. A zoom lens, on the other hand, would work better in a situation where you want to monitor a range of objects such a cars in a large parking lot where the back rows would be out of range for a fixed lens with a short focal length.
There are also two different ways your lens can be mounted in the camera—CS-mount, where the distance between the lens and the image sensor is shorter, and C-mount, where the distance is larger.
How Security Camera Types can Help You
If you know what type of scene your camera will be monitoring, you can look for a camera with a lens designed for that type of surveillance to get the best quality video possible.
Are you installing a camera to monitor a large open space? A wide angle lens with a longer focal length will let you capture more of the room than a telephoto lens with a short focal length. But if you’re looking to capture fine details on objects close to the camera, that telephoto lens would be the best option.
One thing to be aware of, if flexibility is important in your surveillance system, is cameras with multiple lens options. Some cameras let you pick from many lenses so you can customize the camera. While this is not as popular as varifocal lens options, it does give you more choices when building a surveillance system. Some cameras even utilize more than one lens, so a single camera can capture both wide angle video and zoom video.
VideoSurveillance.com offers a wide variety of cameras with different lens options from leading manufactures including Axis, Optica, and Mobotix.
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With a team of knowledgeable sales and technical support representatives, VideoSurveillance.com can help you learn more about video surveillance and select the best cameras for your surveillance needs. Call us at (866) 945-6808 or send us a message today!