CCTV Lens & Field-of-View Calculator
A wide lens sees more but reads less. Enter the lens, sensor, resolution and distance to get the field-of-view angle, the scene width, and the DORI distances — how far you can still detect, observe, recognise and identify a person. Planning figures; real lenses vary. Runs in your browser.
- Identify (250 px/m — read a face or number plate)8.2 m
- Recognise (125 px/m — recognise a known person)16.4 m
- Observe (62 px/m — see clothing & behaviour)33.0 m
- Detect (25 px/m — spot that someone is there)81.9 m
Planning estimate only — sensor widths and lens angles vary by model, and light, motion and compression all affect real-world identification. Use it to compare lenses, then confirm with a site test.
Related Guides — Deep-dive reading
CCTV Varifocal vs Fixed Lens (India 2026): Choosing the Right Angle of View
Focal length sets how wide and how far a camera sees. What a fixed 2.8mm or 3.6mm lens gives you, when an adjustable varifocal earns its higher price, manual versus motorised, and how to pick the right angle for each spot on an Indian plot.
SecurityCCTV Coverage Planning in India (2026): Think in Coverage, Not Cameras
Plan a home CCTV scheme by the coverage it produces, not the number of cameras you buy: map choke points, overlap so every camera is watched by another, keep entry-to-exit continuity, and set the pixels-per-metre each zone actually needs.
SecurityCCTV Optical vs Digital Zoom (India 2026): Which Actually Sees Detail
Optical zoom uses a real lens to add genuine detail; digital zoom just crops and interpolates pixels you already have. Why big digital-zoom numbers on the box are marketing, and when a varifocal or PTZ optical lens is worth paying for.
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