Security Camera Lens

One of the most common mistakes people make when buying a security camera is not choosing the right lens for their needs. When choosing a security camera lens it is important to understand that different lenses give different fields of view and zoom, therefore certain cameras will be better suited to open outdoor areas and others to confined indoor areas.

Choosing The Right Lens

Selecting the correct camera and lens combination is vital to your security’s effectiveness. The wrong lens can result in a camera monitoring only a fraction of its intended surveillance area, or not being able to zoom to the extent you require. Get the lens right and you’ll be rewarded with a number of benefits, from crystal clear footage at the intended ranges, to no risk of glare from sunlight.

What to Look Out for in a Lens

There are a variety of factors that should be taken into account when choosing a security camera lens. Some of the most important include:

Focal Length

Measured in millimetres “mm”, the focal length of a lens determines how far the camera is able to see. The bigger the focal length, the farther away a camera is able to view, and vice versa. The most common focal length of CCTV cameras is 3.6mm, which gives a 72 degree field of view, and is ideal for indoor application.


Monofocal & Varifocal

Monofocal lenses, also known as ‘fixed’ lenses, are only able to focus at a specific distance. They’re typically a cheaper alternative to varifocal ‘zoom’ lenses, which allow you to adjust the focal length to suit your needs.

Field of View (FOV)

A lens field of view determines the width that you are able to see. A wide angle lens tends to be smaller, around 2.8mm, and gives the user a wider picture. But the downside is a lack of detail. If you want a security camera that allows for you to clearly see detail, such as an intruders face, then a larger focal length is required.


The auto-iris function gives cameras the ability to let in more like during dark conditions, and less light in brighter conditions. This allows for clear footage without the risk of glare and is worth checking for if you’re intending to use a camera outdoors.