General CCTV Problems and Solutions

Most unusable CCTV footage is not the camera's fault. It is the result of decisions made before the camera was mounted: where it points, what light reaches it, how the recording is stored, and whether anyone maintained the system afterwards. These six rules come from the failures we see repeated on site after site.

1. Plan the layout before you buy cameras

Start from the incidents you want recorded, not from a camera count. Ask what could happen under each camera's view, what the loss would be, and how someone would approach the asset. Then draw the coverage on a plan.

• One camera per critical asset is rarely enough; an approach and a close-up view answer different questions.
• Cover entry and exit routes, not just the till or the door.
• Write the plan down and hand it to the installer — a diagram prevents the "we'll put one on the back wall" decision.

2. Record digitally, and keep the recording healthy

Tape-era advice still applies in principle: the recording medium decides how much detail survives. Record to an NVR, VMS or edge SD card, monitor disk health, and never let the archive overwrite itself so aggressively that a weekend's evidence disappears before it is exported.

• Digital recording keeps full resolution and allows remote review, live or recorded.
• Exporting a clip for police or an insurer should take minutes, not a tape duplicator.
• Check retention against the site's real needs — 30 days is a starting point, not a guarantee.

3. Design for lighting, not for daylight

A site that looks perfect at noon can be useless at 23:00. About one case in ten involves comparing a badly lit frame with a reference photo, and the comparison usually fails on light, not on resolution.

• Put light where the camera looks, especially on the routes and the faces that matter at night.
• Watch the sun across the year: low sun facing the lens closes the iris and turns people into silhouettes.
• Prefer even, diffuse light over a bright hotspot that blows out faces.

4. Mount for faces, not for tidiness

Cameras mounted high and pointing down make neat cable runs and useless evidence: caps, hoods and angle hide exactly what an investigator needs. Aim for a view where a person's face is visible at the point they must pass, and accept a less tidy installation.

5. Keep the lens clean and the housing clear

Outdoor housings collect dust, pollen and spider webs; indoor domes collect grease and cleaning spray. A dirty lens softens every frame, and no post-processing recovers detail that was never captured.

• Clean with lukewarm water and a drop of mild detergent or white vinegar, using a soft cloth.
• Avoid aggressive solvents on acrylic housings — they cloud the plastic permanently.
• Add lens cleaning to the maintenance schedule, alongside checking that the view has not been blocked by a new display or a new sign.

6. Prefer a wired network

Wireless links are convenient and remain the least reliable part of most systems, especially in storms and on congested 2.4 GHz sites. Where cable can be run, run it: PoE over copper gives power and data on one tested path.

That is where the network layer becomes part of the evidence chain: a stable PoE switch with enough budget, tested cable and, on outdoor or industrial sites, an industrial switch that survives the cabinet's temperature. For runs beyond 100 m, optical converters keep the link on fibre instead of degrading it.

The six rules at a glance

If you are specifying the network side of a surveillance project, send the camera list and site plan — we will size the PoE budget, uplink and cabinet for it. Talk to our team.

FAQ

Les spécifications techniques détaillées sont fournies en anglais.