Skill: CCTV Camera Resolutions and Their Practical Implications
Skill level: 3
CCTV & Networking
Learning Objective
Learn what different CCTV camera resolutions mean — such as 1.3MP, 4K, and 720TVL — and how they impact image quality, storage, zoom clarity, and what can realistically be captured on screen. Understand which resolutions suit which applications.
1. Overview
Camera resolution defines how much detail a CCTV camera can capture. More pixels = more clarity — but also bigger file sizes, larger monitor, higher costs, and greater strain on networks and storage.
Engineers must know how to interpret resolution numbers in real-world terms: what can actually be seen, how clearly, and what limitations exist when recording, storing, and replaying footage.
2. Tools & Reference Materials
CCTV spec sheets (camera datasheets, NVR specs)
Test monitor or laptop with VMS software
Calculator app (for storage/bandwidth planning)
Manufacturer resolution comparison charts
PPE (if working on-site during testing/installation)
3. Before You Start
Check the customer’s requirements: Do they want general observation, or detailed identification?
Confirm the recorder (NVR/DVR) supports the target resolution.
Verify the network bandwidth and HDD capacity for high-resolution streams.
Ensure the display/monitor matches the resolution being installed (e.g., a 4K monitor for 4K cameras).
4. Resolution Formats & Practical Implications
📺 Common CCTV Resolutions
FormatPixel SizeMegapixels (MP)Notes720TVL~960 × 576~0.5MPAnalogue-era quality, standard definition1.3MP1280 × 9601.3MPEntry-level HD, acceptable for low-risk areas2MP (1080p)1920 × 10802MPFull HD, most common baseline today4MP2560 × 14404MPClearer images, good for medium-range detail5MP2592 × 19445MPHigh detail, common in mid-tier IP systems8MP (4K)3840 × 21608MPUltra HD, excellent zoom potential
🔍 More Resolution = More Detail
Clearer digital zoom (important for faces, number plates, or text).
Better playback evidence quality.
💾 More Resolution = More Storage
4K cameras generate much larger file sizes.
Storage planning is critical — HDD size directly impacts retention period.
📶 More Resolution = More Bandwidth
IP systems must support higher throughput for 4K streams.
Ensure switches and NVR network ports are capable.
🖥️ Display Quality Matters
A 4K camera only shows its full benefit on a 4K monitor.
On a standard screen, 4K may appear no different to 2MP.
📦 Recording Time Guide (Approximate, Continuous Recording at 15fps)
HDD Size2MP Camera4MP Camera8MP Camera1TB~14 days~7 days~3–4 days2TB~28 days~14 days~7–8 days4TB~56 days~28 days~14–16 days
(Figures assume standard H.265 compression, medium motion scenes. High motion = shorter retention; motion-triggered recording = longer retention.)
✅ Our Recommendation:
Always allow 1TB per camera channel on the NVR/DVR, even if not all channels are in use.
This future-proofs the system — leaving space if more cameras are added later.
Gives flexibility to increase frame rate, quality, or retention if needed.
4.B
Bandwidth requirements for CCTV NVRs and DVRs refer to the amount of data that must be transmitted over a network or stored on the recorder. It determines how smoothly video can be viewed live, recorded, or accessed remotely.Here’s a brief breakdown:
NVR (Network Video Recorder):
Uses IP cameras connected over a network (LAN or Internet).
Bandwidth is crucial because each camera streams digital video data to the NVR.
Total required bandwidth = sum of all camera bitrates (e.g. 8 × 4 Mbps cameras = 32 Mbps).
Bandwidth limits matter:
Incoming (recording) bandwidth — how much data the NVR can receive and store.
Outgoing (remote viewing) bandwidth — how much it can transmit to users viewing live feeds.
DVR (Digital Video Recorder):
Uses analogue cameras connected via coaxial cable, so recording bandwidth isn’t network-dependent.
Bandwidth only matters for remote viewing or network playback, which use compressed video streams.In short:
NVRs are network-dependent — need sufficient LAN/WAN bandwidth.
DVRs are local-recording systems — network bandwidth mainly affects remote access only.
There is a chart below that shows how camera resolution affect bandwidth requirements. You need this amount of bandwidth PER CAMERA
5.A Application Guidance – Choosing the Right Resolution
Use 1.3MP–2MP for:
General observation areas.
Driveways or gateways where only presence needs confirming.
Budget-conscious installs.
Video intercoms, they usually come in 1.3MP resolution
Use 4MP–5MP for:
Residential jobs needing clear facial/vehicle detail.
Car parks or warehouse loading bays.
Medium-distance views where playback zoom is required.
This is todays standard resolution and we use it for most home security situations.
Use 8MP/4K for:
Long driveways or wide commercial sites.
Entrances with ID requirements.
High-security sites needing detailed evidence.
Customers who specifically request the best.
6. Common Mistakes to Avoid
🚫 Over-specifying 4K when unnecessary (wastes storage & bandwidth).
🚫 Expecting clean zoom from a 1.3MP image.
🚫 Using high-res cameras with old recorders or low-capacity HDDs.
🚫 Viewing 4K on a poor display and assuming “it’s no better.”
🚫 Forgetting that lens, lighting, and positioning matter as much as resolution.
7. Safety Information
While resolution planning itself carries minimal physical risk, installation/testing does involve normal site hazards. Always follow:
SSOW – Use of Test Equipment & Laptops on Site
SSOW – Electrical Safety for IP and Coax Systems
RAMS – Working at Height for Camera Installation
SSOW – Safe Manual Handling (when installing monitors or DVR/NVR units
