CCTV Planning Tool · 09 of 10

Low-Light Suitability Estimator

Will your camera actually see in low light? Scene illumination, sensor size, lens aperture, IR coverage, and WDR all need to line up against the use case. Check all five in one pass — and get specific fixes when something's short.

The four factors that decide low-light performance

Cameras don't see in the dark — they just need a minimum amount of light to register a usable image. If that light budget is short for what you're asking the camera to do, the result is grainy footage, motion smear, or a black frame. The trick is balancing scene illumination, the camera's sensor, the lens, and any supplementary IR.

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Light budget at sensor
Scene illumination (lux) × aperture (f-number)² × sensor size factor — all compared to the camera's minimum-illumination spec. Headroom is measured in dB; below 0 dB the sensor is below noise floor.
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Sensor capability
Larger sensors gather more photons per pixel and have lower noise floors. 1/2.8" is baseline; 1/1.8" is "good for night"; 1/1.2" "starlight" sensors can produce colour at moonlight levels.
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Use-case fit
Motion detection needs ~1× headroom (any image will do). Observation: 3×. Recognition: 30×. Face / plate: 100×. Court-grade identification: 200×+. The bar is much higher than installers usually realise.
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Mixed-light handling (WDR)
Doorways, parking exits, vehicles with headlights — these need WDR (90 / 120 / 140 dB ratings). Without it, bright zones clip white and dark zones go black, even when the average lux is fine.

Pick the use case

Each tier has its own light-budget threshold. Pick the one that matches what you need the camera to do at the worst-case time of day.

Or start from a real scenario

These presets cover common Indian deployments where low light is the question. Click any to load camera + scene + lighting, then tweak.

Check your setup

Scene illumination

Pick the worst time you need the camera to work. Outdoor deployments must use the night-time level.
Strong = vehicle headlights / sun + shade. Extreme = direct sun in frame.

Camera spec

Lower f = more light. f/1.6 is typical for fixed-focal CCTV; f/2.0 for varifocal.
From the datasheet — the lower the better. Assumed quoted at f/1.6 (industry standard).
B&W mode gives roughly 5× sensitivity boost. Dual-sensor (one colour, one mono+IR) is best for 24/7.

IR illumination & range

Built-in or external. Must reach the subject. 850 nm has slight red glow; 940 nm is invisible but 50% less efficient.

Low-light verdict

SUITABLE
Camera will perform reliably at this light level
Light budget, sensor, and use-case all line up.
95 / 100
Lux ladder — where you sit
IR coverage

Findings & fixes

Recommendations at current scene

Refine your plan with IndoAi's companion tools

Low-light suitability is one piece of the deployment. The other planning tools handle the rest — face rec and ANPR feasibility (both very low-light dependent), pixel density, and the right lens choice for night-time fields of view.

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Face Rec Feasibility
Face recognition needs both adequate pixels AND enough light — check both.
Check face rec →
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ANPR Feasibility
Plate-read pipeline depends heavily on IR illumination at night.
Check ANPR →
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PPM Calculator
Pixel density on the target — the other half of the visibility equation.
Check PPM →
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Lens Selector
Pick the right focal length to keep IR coverage matched to the field of view.
Pick lenses →

Get this report as a PDF

A branded report with the suitability verdict, four sub-scores, light budget calculation in dB, IR coverage check, recommended sensor / aperture / illuminator, and the optimisation limits. Useful for customer quotes, installer briefs, or internal sales.