CCTV Resolution Explained: 2MP vs 4MP vs 4K — What Do You Actually Need?
By the DC Fire & Security engineering team — installing and maintaining fire and security systems since 2010. Updated June 2026.
Quick answer
4MP (2K) is the sweet spot for most homes and businesses — sharp enough to identify a face at 8–10 metres at sensible cost. 2MP (1080p) is fine for overview and confined spaces like hallways. 4K (8MP) earns its premium where you need identification at distance, digital zoom into wide scenes, or number plates — not on every camera.
What does resolution actually buy you?
Pixels on target. Identification needs roughly 250 pixels per metre at the subject; recognition of a known person needs about 125 px/m. A 2MP camera with a standard lens delivers identification out to roughly 5–6 metres, 4MP to about 8–10 metres, and 4K to 15 metres or more. Beyond those distances you get 'something happened' footage, not 'this person did it' footage.
| Resolution | Identify a face | Read a plate (still) | Best use |
|---|---|---|---|
| 2MP / 1080p | to ~5–6m | to ~8m | Hallways, small rooms, doorways |
| 4MP / 2K | to ~8–10m | to ~12m | Driveways, shopfronts, gardens — the default choice |
| 4K / 8MP | to ~15m+ | to ~20m | Car parks, yards, wide scenes needing zoom-in |
When is 4K worth the money?
When one camera must cover a wide area and you'll want to zoom into recorded footage afterwards — car parks, yards, school playgrounds, retail floors. A single 4K camera often genuinely replaces two 2MP cameras. It is wasted on a porch camera three metres from the door, and it quadruples storage versus 1080p unless bitrates are managed, which is why we mix resolutions per position rather than selling '4K everything'.
What matters as much as resolution?
- Lens choice: a 2.8mm lens is wide but short-range; a 4mm or 6mm lens trades width for reach — matching lens to position beats adding megapixels
- Low-light performance: a good 4MP sensor at night beats a cheap 4K sensor that smears in the dark; ColorVu/full-colour night cameras change identification quality after dark
- Mounting position: a perfectly sharp camera at 5 metres height looking down on heads identifies nobody — angle beats everything
- WDR (wide dynamic range): essential for cameras facing doorways and headlights
Frequently Asked Questions
Is 1080p still acceptable for business CCTV?
Do higher-resolution cameras need better cables?
Can I upgrade just one camera to 4K on an existing system?
What resolution do police want?
Need help from a professional installer?
We install and maintain fire and security systems across Bedfordshire, Hertfordshire and London — with fixed written quotes, a 36-month warranty, and certification your insurer will accept.
Request a free survey
Free site visit · No obligation · Response within 24 hours