A Guide to CCTV Camera Resolution

One of the considerations that anyone makes when specifying security cameras is the CCTV Camera Resolution. But what is it, and how does it compare against what we’re used to, such as 1080p TV? To understand this we first need to understand what a ‘pixel’ is.

The Humble Pixel

If like me you were born in the 80’s and grew up in a house with a boxy CRT television, chances are you probably put your hair against the static screen to fool your parents you have been electrocuted…

Whilst doing so, you probably looked right into the screen and saw something similar to the below?  

What you actually see here are the individual pixels of red, green and blue light that together make an ‘image’.

The density of these pixels (how tightly they are packed together) is what we call resolution.

So what is Megapixel?

A megapixel or MP simply means a million pixels. It is just one of the methods in which resolution (the pixel density) is measured.  

So what about my 1080p TV?

Rather strangely TV manufacturers continued to measure their resolution in the number of vertical pixels on the screen. This dates back to old analogue TVs where resolution was measured in television lines (or TVL).

In essence 1080p means 1080 pixels horizontal.

When using the widescreen aspect ratio of 16:9 (16 units horizontal is equal to 9 units vertical) you get a horizontal figure of 1920 pixels. To calculate what this means in megapixel, you multiply these numbers together to get a figure of 2,073,60 – 2 and a bit megapixel.

So what is 4k?

Where a resolution is measured in “k” manufacturers are again talking about the vertical number of pixels. 4k in vertical pixels equates to 3840 (it’s close to 4,000). Using the same calculation as above will give you a figure of 8,294,400 pixels or an 8mp image.  

For a better insight into resolution comparison, see the chart below:

CCTV Camera Resolution vs TV formats