Digital IP versus analogue CCTV cameras

There was a period when the CCTV market changed underneath everyone, and network cameras went from expensive specialist equipment to the obvious default. Handykam worked with both technologies for around fifteen years and wrote this comparison while that transition was still live. It reads slightly differently now that the argument is settled, but the underlying trade-offs are the ones anybody maintaining an older analogue installation still has to weigh.

The difference in one sentence

An analogue camera produces an analogue video waveform and sends it to a screen or recorder down a dedicated AV or coaxial cable. An IP camera is digital from the sensor onwards and puts its output on a network — with, as the original page put it, bags full of benefits.

Why digital won

Advantages

• Higher resolution. Network cameras run to 4K and beyond. An analogue PAL signal is capped near 976 × 582 pixels regardless of how good the sensor behind it is — see Camera resolution.
• Network and internet ready. No extra hardware is needed to view a network camera on a computer, phone or smart television. Everything else in the house went this way; the cameras followed.
• Multiple streams. One camera can publish several streams simultaneously at different resolutions, so a recorder gets full quality while a phone on a weak connection gets something that actually plays.
• Remote access and control. Settings, not just pictures, are reachable from anywhere.
• Security. The signal can be encrypted. An analogue video signal on a cable cannot be, and is straightforward to intercept.
• Falling cost. Volume brought dedicated chipsets and dedicated chipsets brought prices down.
• Simpler cabling. One network cable carries data and, with Power over Ethernet, power as well. Analogue cameras usually need more than one cable.
• Analytics. Motion zones, line crossing, object classification — processing that lives in the camera rather than in an operator.
• Existing infrastructure. Most buildings already have a network, and often WIFI, to plug into.

Disadvantages

• Setup cost and effort. Cameras have to be configured, addressed and secured, which takes time an analogue camera does not.
• Storage. Higher resolution means substantially more disk. The arithmetic is worked through in the DVR and NVR FAQ.
• Complexity. More features mean more to learn, and more that can be set wrongly.
• Network dependency. A network camera is only as reliable as the network it sits on, and it inherits the network's security problems along with its convenience. A camera reachable from the internet with a default password is a genuine liability — see the ICO's guidance on the obligations that come with recorded footage.

Where analogue still made sense

Advantages

• Cost. Analogue systems were cheaper, and remain cheaper to extend if one is already installed.
• Maturity. Decades of installations, plenty of people who understand them, and no configuration at all — plug it in and it works.

Disadvantages

• Frame rate and quality well below network cameras.
• More cabling, since power and signal are usually separate for anything beyond a short domestic run.
• No encryption. The signal is easy to intercept.

The wildlife camera view

For a nest box specifically the calculation is a little different from a security installation. Analogue kit is simpler, has nothing to configure, keeps working when the broadband does not, and produces a perfectly good picture of a bird 150mm from the lens. Network kit gives a much sharper image, records to a card in the camera, and can be watched from a phone in another country. Both are legitimate. Handykam sold both for years and moved decisively to network cameras only at the end, when the price and the setup experience had both improved enough.

Converting rather than replacing

An existing analogue camera does not have to be thrown away to gain network viewing. An IP converter digitises the analogue signal and presents it to the router, which is often the cheapest way to modernise a working installation — particularly one with a long cable already buried in a garden.

Related pages: How do IP cameras work? · How an analogue camera works · Cornwall CCTV · CCTV glossary