Security Cameras

Choosing IP and analogue security cameras for indoor and outdoor surveillance

The camera is the part of a CCTV system that records the picture; everything else exists to support it. Choosing the right camera depends on where it is mounted, what it needs to see, and how the recorded footage will be stored and reviewed. The category covers the four main camera body styles in IP and analogue versions.

What this category covers

Dome cameras (compact, indoor or vandal-resistant outdoor), bullet cameras (long-range outdoor with cylindrical body), PTZ cameras (motorised pan, tilt and zoom for wide-area coverage), and turret cameras (a hybrid of dome and bullet styles). Resolutions from 2 MP (1080p) up to 12 MP, with IR night vision range from 10 to 50 metres on commercial models.

How to choose a security camera

Pick the body style for the install

Dome cameras suit indoor ceilings and discreet installs; vandal-resistant versions handle public spaces. Bullet cameras are visible deterrents at building exteriors with longer effective range. PTZ cameras cover large areas (car parks, warehouses) with one camera that pans and zooms but only watches one direction at a time. Turret cameras combine the lower profile of dome with the visible IR ring of bullet, often the modern default for general use.

Match resolution to the scene

2 MP (1080p) covers small rooms, doorways and tills with face recognition at close range. 4 MP and 5 MP cover larger rooms and parking areas. 8 MP (4K) and 12 MP cover wide outdoor areas where one camera replaces several lower-resolution cameras. Higher resolution generates more storage; balance against retention requirements.

Confirm IP rating for outdoor cameras

IP66 protects against rain and dust; IP67 adds short-term immersion protection. Outdoor cameras should be IP66 minimum; locations with extreme weather or wash-down environments need IP67 or higher. Indoor cameras have no IP rating because they don't need one.

Plan IR night vision range

Bullet and turret cameras include IR LEDs with rated range from 10 to 50 metres; the rated range is the maximum, with practical clear-image range usually two-thirds of that. PTZ cameras with motorised IR can illuminate further. For pitch-dark sites, a colour-night-vision camera with low-light sensors gives better detail at the cost of needing some ambient light.

Key features to compare

ONVIF compliance

ONVIF is the industry standard for IP camera and NVR (Network Video Recorder) interoperability. ONVIF-compliant cameras work with any ONVIF-compliant NVR or video management software. Specifying ONVIF compliance avoids vendor lock-in.

Lens type

Fixed-focal-length lenses cover one angle of view; varifocal lenses adjust the field of view at install time. Motorised varifocal lenses adjust remotely from the NVR software. The right lens depends on what the camera needs to see and from how far.

Onboard storage

Some cameras include an SD card slot for local recording, useful as a backup if the NVR connection fails. Most professional installs route everything to a central NVR; the SD card is a redundancy layer.

What to check before buying

• Indoor or outdoor, and the corresponding IP rating?
• Body style matched to the install (dome, bullet, PTZ, turret)?
• Resolution sufficient for the scene without overstocking storage?
• IR range adequate for the scene at night?
• ONVIF compliant for compatibility with the NVR or software?

Frequently asked questions

How many megapixels do I need on a security camera?

For tills, doorways and small rooms, 2 MP (1080p) gives readable detail. For larger rooms and parking areas, 4 MP balances detail and storage. For wide outdoor areas where one camera replaces several, 8 MP or 12 MP justifies the higher storage cost. Going beyond what the install needs just fills the NVR.

Do PTZ cameras replace fixed cameras?

One PTZ camera can cover an area but only watches one direction at a time. While the PTZ is looking left, anything happening to the right is missed. Most installs use fixed cameras for full coverage and a PTZ as a follow-up zoom on activity. Treating PTZ as a complete coverage solution leads to gaps.

What is the difference between IR and colour night vision?

IR (infrared) night vision uses invisible IR LEDs and produces a black-and-white image in complete darkness. Colour night vision uses larger, more sensitive sensors and shows colour images at low light, but needs some ambient light (street lights, security lights). For pitch-dark sites IR works; for sites with some ambient light, colour gives more useful identification.

Are cheap cameras from Amazon as good as branded?

Some are competent at home use; many fail under sustained outdoor exposure or have poor firmware support. Branded cameras (Hikvision, Dahua, Axis, Bosch) cost more but offer longer firmware updates, longer manufacturer warranty and better integration with NVRs. For home use, mid-range branded cameras are the safe choice; for commercial, professional-tier branded only.

Can I retrofit IP cameras into an existing analogue install?

Yes, with a hybrid NVR that accepts both analogue and IP inputs. Some installers replace cameras gradually, swapping analogue for IP one camera at a time. Coaxial cabling can be reused with EoC (Ethernet over Coax) adapters, though new CAT6 runs are usually cleaner.