CCTV Lens Size WHY?

CCTV Camera Lens Size/Types and why Accrington Aerials don’t install kits.

There are many different lens size and type within the CCTV industry each has its own benefits to help fine tune an installation to the customer’s needs.

Lens Sizes

Ok so what do the numbers actually mean. 2.8mm 4mm 6mm What is the difference?

First of all the greater the number (i.e. the bigger lens) the more zoomed in the image will be. This means that the smaller the number the wider the angle of the image.


When it comes to CCTV a 2.8mm lens is usually the smallest lens size (widest angle) these are found in most CCTV Kits and are perfect for installations where a lot of the area immediate to the camera needs to be viewed. These wide angle cameras work best when there is a wide open space around them.

Wide angle cameras are NOT recommended when looking down a corridor or wall due to the fact the extra viewing angle will be wasted on the wall near the CCTV camera. As well as this the IR is most likely to reflect back into the lens causing a poor picture at night.


The 4mm lens is suitable for the largest number of domestic installations. Onscreen you will notice that the camera is more zoomed in than the 2.8mm but is wide enough to be used for smaller plots. The 4mm camera is better suited installed along a wall or corridor.


A 6mm lens CCTV camera is usually the largest size available for a fixed lens CCTV camera.

6mm is a lot more zoomed in than the 2.8mm wide angle camera and is good for viewing areas further away. The 6mm CCTV camera is ideal for down tight corridors along walls and Viewing an entrance without the camera directly above it.

These cameras are not suited for inside domestic installations but are ideal for installations when trying to get extra zoom without paying extra for a vari-focal camera.

Lens Types

Fixed lens

Fixed lens cameras are the Best value for money cameras with minimal moving parts and standardised lens sizes these are more reliable and in the hands of a good installation expert a system to suit most needs can be designed quite easy using Different types of fixed lens CCTV cameras for different environments.


To put it simple a vari-focal CCTV camera is a camera that will zoom in and out.

On budget Vari-focal CCTV cameras you would need to adjust the zoom and focus at the cctv camera.

Most better quality Vari-focal CCTV Cameras now come motorized this allows the user to adjust them from the Nvr/Dvr / App or web browser.

Vari-focal CCTV cameras are the ideal candidate for those installations where the installer needs to zoom and focus on to a particular item and location. A good well trained installer can fine tune these CCTV cameras to exactly where you need them.

Vari-focal cameras can be larger than fixed lens cameras due to the equipment inside them and are considerably more money to buy.

Pan Tilt Zoom PTZ

Not really a lens type this is a CCTV camera that can do as it says. With built in motors the camera can move in any direction you require most not all of the pan tilt CCTV cameras also zoom PTZ.

PTZ Cameras have lots of benefits and offer a lot of flexibility smart tracking object removal the list goes on. If partnered with other applications these CCTV cameras can be programmed to open mag locks security gates garage doors etc all while keeping the data within the NVR.

Due to the size and cost of these cameras they are normally used in a commercial environment. However as time goes by the ptz camera is getting smaller and more affordable to the domestic market.

Fish eye

The fish eye is the CCTV camera you see in your local shopping centre or airport lounge.

The fish eye generates a distorted circular image with a ultra-wide angle picture. Good if you need to view an entire scene. The footage can be split and modified to provide individual views.

Rarely is the fish eye CCTV camera used for the domestic market.

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