On this page
01. The numbers02. Pixel density: the number that actually matters03. The cost of more pixels04. FAQ
Higher resolution means more pixels and more potential detail, but detail on a person depends on pixel density: how many pixels land on the target. A 2MP camera close to a door can identify faces better than an 8MP camera covering a wide yard. More pixels also mean more storage and bandwidth.
Key takeaways
- 2MP = 1920×1080, 4MP = 2560×1440, 8MP = 3840×2160 (4K).
- What matters is pixels per metre on the target, not megapixels alone.
- Doubling resolution roughly doubles storage and bandwidth at the same compression.
- Use higher resolution where you need detail across a wide view, not everywhere.
01The numbers
| Resolution | Pixels (typical) | Common name | Typical use |
|---|---|---|---|
| 2MP | 1920 × 1080 | Full HD / 1080p | Doors, corridors, close-range views |
| 4MP | 2560 × 1440 | 2K / 1440p | General all-round coverage |
| 5MP | 2560 × 1944 (varies) | 5MP | Common on HD/Turbo HD systems |
| 8MP | 3840 × 2160 | 4K / UHD | Wide areas needing detail: yards, car parks |
02Pixel density: the number that actually matters
The international CCTV standard IEC 62676-4 describes what an image can be used for based on pixels per metre (px/m) on the target:
| Purpose | Pixel density | What you can do |
|---|---|---|
| Detect | 25 px/m | Tell that a person is there |
| Observe | 62 px/m | See what a person is doing |
| Recognise | 125 px/m | Recognise someone you know |
| Identify | 250 px/m | Identify a stranger beyond reasonable doubt |
A 1920-pixel-wide image covering a 7.5 m wide doorway area gives about 256 px/m (enough to identify). The same camera covering a 30 m yard gives about 64 px/m (only enough to observe).
03The cost of more pixels
- More storage per camera per day
- More network bandwidth, especially for remote viewing
- More demanding recorders and cameras
- Poorer low-light performance on some small, high-resolution sensors
Efficient compression like H.265 reduces the storage cost. See H.264 vs H.265 and the storage calculator guide.
04Frequently asked questions
Is 4MP better than 2MP for CCTV?
It gives more detail across the same view, which helps on wider scenes. For close views like a doorway, a good 2MP camera can be enough.
Is 8MP (4K) worth it?
For wide areas where you need detail, yes. It needs more storage and bandwidth, so it's usually used selectively rather than on every camera.
Why is my high-resolution camera blurry at night?
Low light, motion blur and compression all reduce detail at night. Sensor size, lens aperture and lighting matter as much as resolution.
