Quick Answer
For most residential and small commercial installations in Northern Ireland, 4MP is the sweet spot in 2026. It delivers enough detail to identify faces and licence plates without the storage costs of 8MP. 2MP is fine for basic perimeter coverage where identification isn’t critical. 8MP (4K) is justified for large commercial sites, car parks, or anywhere you need to capture fine detail across wide areas.
Choosing the right camera resolution is one of the most common questions we get from customers in Northern Ireland. It impacts everything from the cost of your NVR to how long recordings are stored.
This guide cuts through the marketing to give you practical advice on what each resolution means for your security system.
What Do the Numbers Mean?
MP (Megapixel) refers to the number of pixels in the camera’s image sensor. More pixels means more detail.
| Resolution | Pixels | Common Use |
|---|---|---|
| 2MP (1080p) | 1920 x 1080 | Basic coverage |
| 4MP (2K) | 2560 x 1440 | Recommended standard |
| 5MP | 2592 x 1944 | Enhanced detail |
| 8MP (4K) | 3840 x 2160 | Maximum detail |
2MP (1080p) — When It’s Enough
2MP cameras are the entry level in modern CCTV. They capture Full HD footage and are suitable for:
- Basic perimeter monitoring
- Properties where you just need to see activity, not identify individuals
- Budget-conscious installations
- Areas with limited storage capacity
NI Consideration: Many older CCTV systems installed before 2020 are 2MP. Upgrading to at least 4MP gives meaningfully better results, especially for identification.
4MP (2K) — Our Recommended Standard
4MP has become the default recommendation for most installations. It offers:
- Clear facial identification at 5-8 metres
- Licence plate capture at close range (under 5 metres)
- Good low-light performance with modern sensors
- Manageable file sizes (about 25% larger than 2MP)
For most homes and shops in Northern Ireland, 4MP is the right choice. You get significantly more detail than 2MP without the storage demands of 8MP.
5MP — The Middle Ground
5MP cameras offer a step up in detail but with some trade-offs:
- Sharper images at greater distances
- Requires more storage and bandwidth
- Benefits from higher-quality lenses to realise the extra resolution
We typically recommend 5MP when:
– You need detail at medium distances (10-15 metres)
– You have an NVR that supports it
– Storage capacity isn’t a constraint
8MP (4K) — When Size Matters
8MP cameras capture four times the pixels of 1080p. They’re justified when:
- Covering large open areas (car parks, warehouses, sports fields)
- You need to identify people or objects at distance
- You have the storage infrastructure to support it
- License plate capture across multiple lanes
Storage reality: An 8MP camera recording 24/7 needs roughly 4x the storage of 2MP. A 4-camera 8MP system recording continuously needs substantial NVR storage.
Real NI Example
A convenience store in Coleraine had an old 2MP system. Faces were recognisable but not identifiable on the recordings. We upgraded to 4MP cameras at the entrance and till area. Now facial features are clear enough for police identification if needed, and the upgrade cost was modest compared to going to 8MP throughout.
How Resolution Affects Storage
| Resolution | Daily Storage (per camera) | 30-Day Storage (4 cameras) |
|---|---|---|
| 2MP | ~25GB | ~300GB |
| 4MP | ~40GB | ~480GB |
| 8MP | ~100GB | ~1.2TB |
These are estimates for H.265 compression at standard quality settings. Actual usage varies based on scene activity, compression settings, and whether you use motion-triggered recording.
Tip: We always recommend getting the largest NVR storage you can afford. Storage is cheaper than better cameras.
Frame Rate Considerations
All Dahua cameras we install support at least 25fps (frames per second), which is smooth enough for most purposes. For specific applications:
- Standard surveillance: 25fps is fine
- Capturing fast movement (cash handling, entrances): 30fps helps
- Licence plate capture: Some cameras offer 60fps but you need the right model and lighting
Frequently Asked Questions
Q: Can I mix different resolutions on the same system?
A: Yes. Most modern Dahua NVRs support cameras of different resolutions. This can be useful if you want 4MP cameras for key areas and 2MP for basic coverage elsewhere.
Q: Does higher resolution mean better low-light performance?
A: Not necessarily. Low-light performance depends more on the sensor size and technology (Dahua Starlight, for example) than resolution. A 4MP Starlight camera will outperform an 8MP camera with a basic sensor in low light.
Q: How does Wi-Fi affect camera performance?
A: This is critical: we always recommend wired (PoE) camera connections over Wi-Fi. Wired connections provide stable, interference-free video with no bandwidth limitations. Wi-Fi cameras suffer from signal interference, latency, and bandwidth constraints that affect video quality. If running a cable isn’t possible, we use Ubiquiti wireless bridges to create a reliable point-to-point link, but the cameras themselves are always wired.
Q: What’s the minimum宽带 speed for remote viewing?
A: For remote viewing via the Dahua DMSS app, you only need an upload speed at the property of roughly 2Mbps per 4MP camera stream. Most broadband connections in Northern Ireland easily handle this.
Q: How long should I keep recordings?
A: For most homes and businesses, 14-30 days is practical. High-risk premises (cash businesses, warehouses) may want 60+ days. Your NVR storage capacity and whether you use motion-triggered recording affect this.
Summary
| Choose 2MP if… | Choose 4MP if… | Choose 8MP if… |
|---|---|---|
| Budget is primary concern | You want clear identification | You cover large areas |
| Basic perimeter coverage | Most home/business use | You need maximum detail |
| Limited storage available | Best value for money | Storage isn’t a constraint |
Ready to Choose?
Advanced Overwatch provides expert advice on camera selection as part of our free site surveys. We’ll assess your property and recommend the right resolution for your specific needs and budget.
Contact us for a free survey — we’ll demonstrate cameras at different resolutions so you can see the difference yourself.
