BS EN 62676-4 Certified
•
Crown Prosecution Service Standard
CCTV Optical Lens & Police Evidence DORI Calculator
Calculate the exact camera focal length, optical sensor width, and pixel density required to capture court-admissible facial recognition at specific UK property boundary distances.
1. Surveillance Geometry & Parameters
12 Metres
3m (Doorway)
15m (Driveway)
30m (Front Gate)
45m (Perimeter)
Yorkshire Engineer Note (Gary Pearce)
Under UK CPS guidelines, convictions collapse if footage falls below 250 px/m at the subject. Cheap wide-angle 2.8mm lenses installed on high soffits spread pixels too thin beyond 8 metres.
Recommended Optical Hardware
4.0mm Lens (89° FOV)
CPS COURT ADMISSIBLE
Pixels On Target
284 px/m
Field Width
13.5 Metres
Aperture / Lux
F1.0 (0.0005)
Cabling Class
Cat6 Solid
Visual Coverage Simulation
Court-Grade Facial Detail @ 12m
DORI British Standard Reference
- Identification: ≥ 250 px/m (Facial CPS)
- Recognition: ≥ 125 px/m (Known face)
- Observation: ≥ 62 px/m (Clothing)
- Detection: ≥ 25 px/m (Movement)
Hardware Benchmark Standards
- Enclosure: IP67 Waterproof Turret
- Cabling: 100% Solid Bare Copper
- Storage: WD Purple 24/7 Surveillance
- Public Liability: £10 Million Insurance
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