CCTV Selection
& Design Guide
Complete technical reference for forensic-grade surveillance — from lens selection and DORI targets to network hardening and defensible, right-sized storage.
Applicable Standards
National Building Code of India – 2016 (NBC) Bureau of Indian Standards (BIS) CPWD General Specifications STQC Certification for CCTV Products IEC 62676 Series (Video Surveillance) ITU-T Recommendations (Cyber Security) ISO/IEC 27001 (Information Security) CERT-In Guidelines (Cyber Security)
Design Considerations
Site survey & risk assessment Field of view (FOV) & coverage Lens selection & PPM calculation Lighting analysis (min. lux) Network design & bandwidth Storage calculation & retention Power backup & redundancy Environmental & vandal risk Cyber security & data privacy Testing, commissioning & handover
Camera types
STQC & Certifications
STQC compliance (MeitY, Govt. of India) BIS IS 13252 (Part 1) / IEC 62676 ONVIF conformance (Profile S/G/T/M) ISO/IEC 27001 (information security) CPWD approved products RoHS compliant ISI mark for safety & EMC
Regulations & Guidelines
| Regulation | Applicable For |
|---|---|
| CPWD CCTV Guidelines | Govt. buildings |
| Smart Cities Mission | Urban surveillance |
| Safe City Project Guidelines | Public safety |
| MoRTH (ANPR Standards) | Highway & transport |
| Railway CCTV Standards | Railway premises |
| Airport Authority of India | Airports |
| State Police Specifications | Police surveillance |
| Data Privacy (DPDP Act) | All CCTV systems |
| CERT-In Cyber Security | All IP based systems |
Resolution, PPM, DORI & lens selection
Resolution, PPM & DORI
| DORI (EN 62676-4) | px/m | Meaning |
|---|---|---|
| Monitor | 12.5 | Presence in a crowd |
| Detect | 25 | Someone is present |
| Observe | 62.5 | Distinctive details |
| Recognize | 125 | Know a person |
| Identify | 250 | Beyond doubt |
| Inspect | 1000 | Read a note / plate |
| Resolution | H. Pixels | PPM @20m |
|---|---|---|
| 2MP (1080p) | 1920 | 96 |
| 4MP | 2560 | 128 |
| 5MP | 2592 | 129 |
| 8MP (4K) | 3840 | 192 |
| 12MP (4K+) | 4000 | 200 |
Higher PPM means more detail. Choose a resolution that hits the required PPM for Identify.
Lens Selection Guide
| Lens | Focal | H. FOV | Use |
|---|---|---|---|
| Fixed | 2.8mm | ~98° | Wide area |
| Fixed | 4mm | ~75° | General |
| Fixed | 6mm | ~50° | Corridor |
| Fixed | 8mm | ~38° | Long distance |
| Fixed | 12mm | ~26° | Perimeter |
| Fixed | 16mm | ~19° | Far distance |
| Varifocal | 2.7–13mm | ~98–28° | Flexible |
| Motorized | 5–50mm+ | ~60–6° | PTZ |
| Optical zoom | x20–x60 | Depends | Distance |
FOV depends on sensor size — verify with an FOV calculator before final lens selection.
Night Vision (IR)
| Type | Tech | Range |
|---|---|---|
| IR 850nm | Standard | 20–30m |
| IR 850nm | High power | 30–80m |
| IR + White | Hybrid | 20–50m |
| Starlight | Ultra low | Colour |
| Thermal | Imaging | Depends |
Range varies with scene, lens & reflective surfaces.
Camera Features
Environmental & Durability
| IP Rating | IP66 / 67 / 68 |
| Vandal Rating | IK10 |
| Operating Temp. | -30° to +60°C |
| Humidity | 10–95% RH |
| Surge Protection | 4kV / 6kV |
| Corrosion Resistance | Anti-corrosion coating |
| UV Resistance | Yes |
| Certifications | CE / FCC / RoHS / BIS |
PTZ Specifications
Optical zoom: x20 – x60 Presets: 300 – 500+ Pan speed: 0.1° – 300°/s Tilt speed: 0.1° – 200°/s Accuracy: ± 0.1° Auto-tracking: yes Protocols: ONVIF, Pelco P/D Pan 360° · Tilt -15° to 90°
Frame Rate Guide
| Application | FPS |
|---|---|
| General monitor | 15 |
| Standard recording | 25 |
| High detail | 25–30 |
| Fast moving | 50–60 |
| Traffic / ANPR | 25–30 |
| Slow motion | 60+ |
Higher FPS raises both storage & bandwidth requirements.
Network Design Best Practices
Storage Calculation
- › Use ÷1000 (drive-label GB), not ÷1024
- › Add +20% VBR / motion headroom
- › Subtract RAID parity & ~7% format loss
- › Motion-only recording cuts 50–75%
Use the live calculator below ↓
RAID Recommendations
| RAID | Use Case |
|---|---|
| RAID 5 | Perf. + 1 fault |
| RAID 6 | Perf. + 2 faults |
| RAID 10 | Perf. + redundancy |
| Hot Spare | Auto failover |
Enterprise / surveillance-grade HDD recommended.
NVR / VMS Selection
Channels & bandwidth Decoding capability Storage capacity RAID support ANR (auto replenish) Failover & redundancy ONVIF / SDK support User management & audit
PoE Switch Guide
| Standard | Source | To Device |
|---|---|---|
| 802.3af (PoE) | 15.4W | ~12.95W |
| 802.3at (PoE+) | 30W | ~25.5W |
| 802.3bt Type 3 | 60W | ~51W |
| 802.3bt Type 4 | 90–100W | ~71W |
Corrections & Expert Notes
Where a commonly-circulated spec chart gets it wrong — and what we use instead.
DORI values (EN 62676-4)
The four-tier table is often invented. The standard actually defines single criteria: Detect 25, Observe 62.5, Recognize 125, Identify 250 px/m — plus Monitor 12.5 & Inspect 1000. Fixed above.
Storage divisor
÷1024 mixes binary/decimal units. Drives are sold in decimal, so size in GB with ÷1000 — then add margin & RAID loss. Fixed in Storage Calculation.
PoE wattage
The af/at/bt figures are source power. Devices actually receive less after cable loss (~13/25.5/51W). Both columns are shown in the PoE Switch Guide.
Missing bitrate data
You can't size storage without bitrate — many charts omit it entirely. Typical per-resolution bitrates are built into the live calculator below.
IR wavelength gap
Only 850nm is usually listed. 940nm is fully covert (no red glow) but ~30% shorter range — choose per discretion need.
H.266 / VVC caveat
Often listed as if standard; in practice it's rarely supported in NVRs/cameras today. Plan around H.265+ for real deployments.
Storage & Drive Capacity Calculator
Multi-camera configuration — add different camera types, resolutions and codecs; every row rolls up into one storage plan.
| Qty | Camera Type | Resolution | FPS | Codec | Audio | Quality | Per-Cam Mbps |
|---|
Capacity estimates use base bitrate (~1 Mbps per megapixel, H.265, standard quality, 25fps) with codec, quality, frame-rate and scene multipliers. Bitrate varies significantly with actual lighting and motion — always validate against manufacturer specs before procurement. Shows raw usable capacity (decimal TB, ~5% filesystem loss per drive).
UPS & Power Backup
| Device | Backup |
|---|---|
| Switch | 30–60 min |
| NVR / Server | 60–120 min |
| Critical Systems | 2–4 hrs |
- › Online UPS · separate circuit
- › Surge protection
- › Grounding & earthing
Installation Guidelines
Mount height: 2.4–4.5m Angle: avoid direct light Cable: Cat6/6A (100m max) Conduit: separate power/data IP-rated enclosures Bend radius per standard Label both ends Test before handover
IoT & Integration
Mobile app · AI analytics · dashboard · edge AI box · access control · alarm · BMS
Cyber Hardening Summary
Change default credentials Strong password policy Enable HTTPS / TLS Disable unused services Keep firmware up to date Network segmentation (VLAN) 802.1X authentication Enable audit log Follow CERT-In guidelines
Design your CCTV system with confidence
Talk to Field Forensic about STQC-compliant camera selection, network design and defensible, court-ready storage planning — DRISHTI CCTV Forensic Analysis Suite, made in India.