Our Hikvision IP camera buying guide goes further on series, suffixes and pixels per metre. Here's the short version.

Where do I start?

Start with what you need to see. Resolution matters less than most people expect. A 4K camera on a wide lens still won't identify a face across a car park. What decides that is pixels per metre at the distance involved, which depends on lens and mounting position as much as megapixels.

More pixels on the same sensor can mean a worse low-light picture. In this range the 4MP ColorVu cameras reach 0.0001 lux, while their 8MP versions reach 0.0005 lux: same sensor, same lens, split across twice as many pixels. For a really dark yard, 4MP is often the better camera.

ColorVu, AcuSense or both?

• ColorVu records in colour after dark using a white light, instead of switching to black-and-white infrared. Look here if vehicle colour or clothing matters. Check the light range against the lens: a camera that detects to 89 m but lights to 30 m won't give colour at the far end of its view.
• AcuSense tells people and vehicles apart from leaves, shadows, rain and animals, which cause most false alerts. It also feeds AcuSearch and AcuSeek on a compatible recorder, and those only work with AcuSense cameras. That's the most costly mismatch we see.
• Active Deterrence models add a strobe and siren that fire on the camera's own rules, so they work on a standalone install. The strobe is white light on /SL models whatever the housing colour, and these models use much more power (see below).

Turret, bullet or dome?

Shape affects mounting, vandal resistance and how the camera looks on a building more than picture quality. Our guide turret vs bullet vs dome covers the trade-offs.

• Turret: the default for most installs. Easy to aim, no dome reflection.
• Bullet: longest light ranges, clearly a camera.
• Dome and Vandal Dome: discreet. Vandal-rated models carry IK10 where the camera is within public reach.
• PTZ: where one camera must cover a large area under operator control.

How much PoE power do I need?

This catches people out. Most plain cameras run on standard 802.3af, some as low as 6.5 W. Add a strobe and siren and the same camera needs 802.3at, usually 16 to 18 W.

The DS-2CD2047G3-LI2UY uses 6.5 W. The /SL version of the same camera uses 16 W. On a recorder with a fixed PoE budget, that's the difference between filling every port and running out halfway. Send us your camera list and switch or NVR model and we'll confirm it.

You'll also need an NVR with enough channels, and a surveillance hard drive sized with the storage calculator.

White, black or grey?

Most models come in all three at the same specification. Black disappears against dark brickwork, steelwork or a slate soffit. Grey suits galvanised steel, render and concrete. White is right where you want the camera seen as a deterrent.

Why Hikvision?

The range is wide enough to match the camera to the job, the smart detection is mature, and cameras, recorders and the Hik-Connect app are designed together. That's not always true of mixed-brand systems. Using coax instead of network cable? See HD analogue cameras and a DVR.

Can I get a trade account?

Yes. Installers and regular buyers can apply for a trade account. You don't need to be NSI or SSAIB approved.