Security cameras

A camera records what happened. It does not stop what is happening. That distinction should drive every decision in your system design — because a camera pointed at an unlocked door is documentation of a burglary, not prevention of one. When cameras are paired with perimeter hardening, door reinforcement, and a practiced response plan, they become a genuinely useful layer. Alone, they are expensive evidence.

Camera functions and limits

Cameras deliver three things: deterrence for opportunistic offenders, real-time detection when someone is monitoring, and post-incident evidence. Studies on retail and residential contexts consistently show that visible cameras deter opportunistic crime — the burglar who sees four cameras on a house will usually move to the next. Determined adversaries are less affected.

The evidence function is often undervalued. A timestamp, a face, a license plate — these transform a vague police report into an actionable lead. That function requires you to actually get the footage, which means your storage must survive the incident. A camera whose NVR sits visible on a shelf gets stolen along with everything else.

Resolution and identification distance

Resolution determines how far away you can identify a face, read a plate, or confirm a detail. The minimum practical standard for identification at an entry point is 1080p (2 megapixels). At this resolution, a well-positioned camera can produce an identifiable face image at roughly 15 to 25 feet (4.5 to 7.5 m). Beyond that range, the image will detect presence but not provide a usable identification.

For driveways, parking areas, or rural approaches where you need useful detail at 40 feet (12 m) or beyond, upgrade to 4K (8 megapixels). A 4K camera provides roughly four times the pixel count of 1080p. The practical benefit: you can digitally crop into a 4K recording and still read a vehicle's license plate from distances that would be completely unreadable from a 1080p frame. For an approach road or gate camera, 4K is worth the cost difference.

The industry measurement is pixels per foot (PPF). Reliable facial recognition requires approximately 80 to 100 PPF. A 1080p camera covering a narrow 8-foot (2.4 m) wide corridor easily meets this; the same camera covering a 30-foot (9 m) wide driveway will not.

Wired vs. wireless

The core tradeoff is reliability against installation effort.

Wired systems (PoE — Power over Ethernet) run a single Cat5e or Cat6 cable to each camera, delivering both data and power through one connection. This eliminates battery maintenance, wireless interference, and the signal dropouts that plague battery cameras in thick-walled homes. Video travels over a closed LAN — there is no cloud intermediary, no subscription fee, and no exposure to internet-based attacks. Installation requires drilling and routing cable, which is a one-time job. For a permanent home setup, wired PoE is the correct choice.

Wireless cameras pair with your Wi-Fi network and are powered by batteries or AC adapters. Installation is easier, placement is more flexible, and they work well in locations where cable runs are impractical — detached garages, barns, exterior gates. The tradeoff: battery cameras must be maintained (most run 1 to 3 months per charge), and wireless transmission can be disrupted by signal congestion, physical obstructions, or a jammer. Wireless cameras that depend on cloud storage lose recording capability if internet access is disrupted.

Hybrid option

Some NVR systems accept both wired PoE cameras and wireless cameras simultaneously. A useful configuration: wired cameras on the home's main structure, battery wireless cameras on outbuildings where cable runs are cost-prohibitive.

Local NVR vs. cloud storage

For preparedness purposes, local storage wins. A Network Video Recorder (NVR) with an internal hard drive stores footage without internet connectivity, without monthly fees, and without reliance on a third-party server that may be unavailable exactly when you need it.

An entry-level 4-channel NVR with a 1 TB hard drive handles continuous 1080p recording from four cameras for approximately 7 to 14 days before overwriting. A 4 TB drive extends this to 28 to 56 days. For most households, two weeks of rolling footage is sufficient — incidents are typically discovered and reviewed within days.

Cloud backup has one legitimate advantage: footage that survives if the NVR is stolen or destroyed. A practical middle-ground is a local NVR as primary storage with cloud upload of motion-triggered clips only. This limits cloud dependency while providing off-site evidence for significant events.

Field note

Store the NVR in a locked, out-of-sight location — a closet, utility room, or locked cabinet. A burglar who grabs the recorder eliminates your evidence. A PoE NVR with remote access can be checked from your phone, but its physical security matters first.

Night vision and IR range

Most cameras sold today use infrared (IR) illumination for night vision. At 0 lux (complete darkness), IR LEDs illuminate the scene invisibly and the camera captures it in black-and-white. The effective range varies widely:

Entry-level cameras: 20 to 30 feet (6 to 9 m)
Standard residential cameras: 60 to 100 feet (18 to 30 m)
Extended-range bullet cameras: 150 to 300 feet (46 to 91 m)

Match the camera's IR range to the distance you actually need to cover. An entry door camera needs 20 to 30 feet (6 to 9 m). A driveway approach camera may need 100 feet (30 m) or more. Oversized IR illumination creates washout at close range — a camera with 200-foot IR pointed at a 10-foot hallway will produce overexposed white frames.

Two IR wavelengths are available. 850nm LEDs emit a faint red glow visible to the human eye. 940nm LEDs are fully invisible but provide somewhat shorter range. For covert operation, use 940nm.

Separate controlled lighting paired with standard cameras often outperforms IR: a motion-triggered 30-watt LED floodlight illuminates a scene in full color, which is dramatically more useful for identification than IR night vision's monochrome image.

Placement principles

Coverage planning starts with a threat model, not with how many cameras came in the kit.

Priority locations:

Main entry door (close range, face-capture angle)
Rear door and side doors
Driveway or gate approach (plate and face at distance)
Garage entry — both the exterior and the interior garage-to-house door
Any location with poor natural visibility or lighting

Overlap and coverage gaps: Each camera should cover the approach to the next camera. If a camera at the front corner of the house can be approached from the side yard without entering its field of view, you have a gap an adversary can exploit. Walk your perimeter and map approach routes before finalizing placement.

Camera height: Mount exterior cameras at 8 to 10 feet (2.4 to 3 m) above ground. High enough to resist tampering, low enough to capture downward-angle face images rather than the tops of heads.

Angle and backlight: Avoid pointing cameras into the sun or toward bright exterior lights. A camera facing west will be useless at sunset. Check angles in the actual lighting conditions you need to cover, including night.

Power backup

Cameras that go dark in a power outage fail exactly when you may most need them. A battery backup (UPS) on the NVR and PoE switch keeps the system running through short outages — a typical UPS unit supporting one NVR and four cameras can provide 2 to 4 hours of runtime at load.

For extended outage resilience, solar-powered cameras with internal battery storage operate indefinitely off-grid. These work well for outbuildings and gate cameras that are already difficult to wire. The compromise is typically lower resolution and wireless-only operation.

Digital security for camera systems

IP cameras are network-connected devices. Unsecured cameras are regularly hijacked, and the footage — or the network access they provide — can be exploited. Minimum requirements:

Change the default username and password on every camera and the NVR before connecting to the network
Update camera firmware at installation and annually
Place cameras on a separate network segment or VLAN, isolated from computers and phones (see cyber security for network segmentation guidance)
Disable remote access features you do not actively use
If using cloud features, enable two-factor authentication on the associated account

Camera system checklist

Cameras are the documentation layer of your security system. The physical barriers in door hardening and perimeter security create the time and noise that detection requires. Neither layer works well without the other.