CCTV lens calculator
The lens decides what a camera can prove, so it is worth settling before installation. Enter the focal length, sensor and resolution, and the calculator returns the angle of view, the width of scene covered and the pixel density at your distance, then compares that detail with the DORI identification thresholds.
Field of view
85°
horizontal angle
Scene width at 10m
18.2 m
what the frame covers
Detail level
141 ppm
Recognise: a familiar person can be recognised, and a plate read
| DORI level | Needs | This setup |
|---|---|---|
| Identify | ≥ 250 ppm | up to ~5.6 m |
| Recognise | ≥ 125 ppm | Yes |
| Observe | ≥ 62 ppm | Yes |
| Detect | ≥ 25 ppm | Yes |
Cameras we stock at 2.8 mm
- 2.8 mm fixedVIPER PRO 5MP 3K ColorVu Camera - 24-Hour Smart Light CCTVAvailable
- 2.8 mm fixed5MP AI IP Dome Camera PoE Face Detection IR Night Vision 256GB SD ONVIF IP67Available
These figures rest on the sensor chosen above, so it is worth confirming the actual sensor size on each camera’s page: keep the focal length the same and a wider sensor will take in a wider view.
How to interpret the result
The trade-off is between coverage and detail. A wide 2.8mm lens takes in a great deal but identifies very little, whereas a 12mm telephoto identifies at distance through a much narrower view. The DORI thresholds in IEC 62676-4 express that trade-off in pixels per metre: a stranger can be identified from 250, a familiar person recognised or a number plate read from 125, events observed from 62, and movement detected from 25.