— CCTV Resolution · Access & reception
Reception / teller counter — identify a face at 4 m
Problem. A reception desk, bank teller line or pharmacy counter needs footage where a face is legally usable — not just 'someone was there'. The scene is a controlled ~4 m-wide choke-point, but the resolution still has to clear the IEC 62676-4 Identify threshold across the whole counter.
Answer. A mainstream 4 MP camera framed on a 4 m counter delivers roughly 640 pixels per metre — comfortably past the 250 px/m Identify tier — so a face crossing the counter is recorded at court-usable density without reaching for a specialist lens or a higher-cost 8 MP head.
02 / In depth
How this preset reads — the engineering view.
CCTV resolution is not a headline megapixel number — it is pixels per metre of the actual scene. IEC 62676-4 (the DORI scale) sets the minimum horizontal pixel density for each investigative outcome: Detect 25, Observe 62.5, Recognise 125 and Identify 250 pixels per metre. 'Identify' is the tier that lets an operator, or a court, state that a specific individual is the person in frame.
This preset frames a 4 MP camera (2560 pixels across) on a 4 m-wide counter. 2560 ÷ 4 = 640 px/m — about 2.5× the 250 px/m Identify minimum. The margin matters: real scenes are never perfectly front-on, faces tilt, and codec compression eats detail, so designing to roughly 2× the tier minimum is the honest way to actually hit it in service.
Read the output as the tier badge and the px/m figure. Widen the scene and the density falls — at 6 m the same 4 MP camera drops to ~427 px/m (still Identify); at 10 m it falls to ~256 px/m, right on the edge. That falloff is the whole reason choke-points are framed tight.
Note what this does not decide: it does not place the camera, choose a lens focal length, set the mounting height or down-tilt, and it says nothing about low light — an Identify-density daytime frame can still be useless at night without the right sensor and illumination. Those decisions follow the density target, they do not replace it.
What this preset deliberately does not solve
- Pixel density is horizontal only — vertical framing, tilt and off-axis geometry all reduce the effective density in a real install.
- Low light, WDR and codec compression degrade usable detail below the daytime pixel-density figure; specify the sensor and illumination separately.
- The tool models one camera over one scene width — it does not lay out coverage, blind spots or overlap for a multi-camera counter.
How this preset differs from its siblings
The sibling preset frames a WIDE 15 m warehouse aisle, where density falloff forces an 8 MP camera just to reach the Identify boundary. This preset is the opposite end: a tight, controlled 4 m choke-point where a mainstream 4 MP head clears Identify with comfortable margin. Use this one when the scene is a counter, doorway or reception line you can frame tightly.
03 / Hydrated calculator
Try the configuration — live.
The calculator below is preloaded with this preset’s state. Adjust any input — your URL stays shareable.
— Calculator · CCTV resolution & pixel density (DORI)
Scene width, resolution — pixels per metre.
Set the horizontal scene width you need to cover and a camera resolution. The calculator returns the pixel density (px/m and px/ft), the DORI tier achieved and the maximum scene width that still meets each tier. IEC 62676-4 criteria, cited.
Pixel density
640
px/m · 195 px/ft
DORI tier achieved
Identify
≥ 250 px/m
Scene width
4.00
m · 4MP
4MP identifies a face up to ~10.2 m wide; recognises up to ~20.5 m. Resolution pixels are nominal sensor formats — real usable detail is reduced by lens, scene, lighting and compression. This is a planning sense-check, not a survey or a camera layout.
A planning link — not a quote.
- resolution
- 4MP · 2560 px wide (nominal)
- scene width
- 4.00 m
- density
- 640 px/m · 195 px/ft
- achieved
- Identify (Establish the identity of an individual beyond reasonable doubt.)
Max scene width per tier — 4MP
| Tier | Min px/m | Max width |
|---|---|---|
| Detect | 25 | 102 m(336 ft) |
| Observe | 62.5 | 41.0 m(134 ft) |
| Recognise | 125 | 20.5 m(67 ft) |
| Identify | 250 | 10.2 m(34 ft) |
| Inspect | 1000 | 2.56 m(8 ft) |
Max width = nominal horizontal pixels ÷ the tier's minimum px/m. Wider scenes than this fall below the tier.
What changes this estimate
- Lens quality, focus & optical resolving power
- Scene contrast, lighting & motion blur
- Codec compression at the recorded bitrate
- Where the subject sits within the field of view
Source
IEC 62676-4 — DORI pixel-density criteria (Detect / Observe / Recognise / Identify)IEC 62676-4 · retrieved 2026-06-27
A planning link — not a quote.
· Other presets for cctv resolution / ppm calculator
· Next
Brief us on the project — with this configuration.
Presets are a typology starting point. The brief wizard captures the room geometry, programme and constraints we need to translate this configuration into a real design.