How a Security Camera Works
Security Camera with IR L.E.Ds
How a Security Camera Works
In order to purchase a good security system, it helps to understand the technology behind security cameras. Whether your digital cameras are sending information using analog or IP format the lenses are usually very similar. In this article we will break down some of the most common features you should look for when choosing a good security system.
Focal Length of Camera Lens:
The focal length of a lens determines how far the camera can see, and is either fixed or variable. Fixed focal length means the focal length can’t change, so you have to position the camera the correct distance from your target area. These lenses are less expensive than vari-focal lenses, which you can adjust manually, and zoom lenses, which you adjust electronically. Adjustable focal lengths are good for when you have a moving target, or if you need to see details in different parts of the scene.
Field of view:
The field of view determines how wide of an area you can see. The bigger the focal lens the wider the field of view is. 2.5-4mm focal length for example gives you a great wide angle view to cover a large area, However details are often distorted at range. This is okay for a general overview of an area, if however you want a more detailed image then you should choose a camera lens with a larger focal length such as 8 or 12mm.
The Iris of a camera lens:
Just like the Iris in your eye, the primary focus of the Iris in a security camera is its ability to adjust the amount of light that enters the lens. A fixed Iris is a good choice for an indoor application, for instance in an area where lighting conditions do not change often. If however you require a camera in an outdoor location or any other location that has frequent lighting changes than an auto-iris lens may be the best solution.
Specialty Lenses:
Telecentric lenses are capable of adjusting the light beams entering the camera so that the focus stays the same no matter what the distance. This is useful if you need an accurate scale at any distance in the camera. Good for determining a suspects potential height or size of a car, etc.
Large Format lenses are designed for high-megapixel cameras with large digital sensors. They have enhanced depth-of-field and contrast and are excellent for close up high-quality images.
Auto-focus zoom lenses automatically adjust the focus when the object or camera shifts positions. This particular feature is very useful for tracking moving targets.
High-Magnification zoom lenses are great for viewing objects are long distance.
Auto-focus High-Magnification Zoom Lens is usually considered the best type of lens. Its ability to adjust to detail at high zoom levels gives you the best chance of identification.
Any camera is better than nothing, but some cameras are far superior than others depending on the situation. If you are still unsure or just want some more information on the many different types of security cameras feel free to come to our showroom at 1850 Kirschner rd. We would be more than happy to explain the differences in models and features as well as which products fit your particular situation.
Spy vs Spy – The Spy Store
Security Alarm Systems
1850 Kirschner Road
Kelowna, BC V1Y 4N6
http://www.spyvsspy.com/
W: 250-868-8812
F: 250-868-0008
Email: info@spyvsspy.com
