Analogue vs HD IP vs HD over Coax
So you have been browsing the web and perhaps are now even more baffled as to which CCTV system suits your needs. Hopefully this updated (Jan 2015) and simplified guide will help to get you started in terms of which road to go down.
Analogue (SD – Standard Definition) CCTV has been around for some time now and in recent years an influx of cheap/affordable kits from the far east have made their way to our shores, meaning CCTV is now affordable to the masses. Analogue CCTV cameras although digital in some ways, provide a standard analogue video signal to the DVR/TV via a coaxial cable (generally speaking) and as such are not packed full of the technology found in the more advanced types of cameras that we’ll get on to next.
Analogue CCTV resolution (quality) is mostly measured in TVL (TV Lines) rather than digital pixels, which is the main limitation here as even with higher 700TVL cameras the DVR will still only record 704 x 480 pixels on the higher D1 setting. It is also worth noting that with the market flooded with these types of cameras that TV Lines is not the only measure of camera quality. Far from it in fact as similar to cramming megapixels into mobile phones, other parts of the camera such as the sensor and lens also determine image quality.
LIKE MOST THINGS YOU GET WHAT YOU PAY FOR so take a look at the following images and notice how the first camera doesn’t handle the lighting very well and you can’t make out the X on the second line of our eyesight test chart where the second 600TVL camera fares better while the 3rd is noticeable clearer: (click to enlarge):
- Cheap (for a multi camera system)
- Still feature packed (mobile viewing etc)
- Adequate for most home users/small businesses for general observation/recording
- Cameras can be plugged directly into a TV unlike newer technologies which must go through a DVR
- Poor resolution in comparison to HD formats (Not going to give you the best chance of recording details such as car number plates etc)
- Limited wireless options (for up to 4 cameras advanced digital wireless solutions from ABUS or similar are the only option really, which includes wireless adapters for your average analogue camera.)
HD IP CCTV
IP CCTV cameras are more than just cameras as they have web server technologies built in to them meaning they can transmit alone directly across existing PC networks including the Internet for direct access without a DVR. This also means some can upload clips of footage and stills to a web server and even utilise on board SD card recording.
There are also greater wireless options with some cameras having short range in built Wifi while all can take advantage of long range Wifi adapters or powerline adapters eliminating the need for long cable runs.
The biggest benefit though of IP technology is the far superior image quality that is available including full HD resolutions:
- Superb resolution and clarity
- Most cost effective stand-alone camera solution with direct remote access
- Feature rich and flexible means of transmission (You can have cameras at multiple sites on one DVR)
- POE (Power Over Ethernet) allows cameras can be powered via the single wired network connection
- More costly for a multi camera system (but our current range is incredible value when compared to what the cost of such quality was in recent years and worth paying for, for many)
HD over Coax
Finally HD Over Coax is the 3rd option to consider, and since we last updated this article it has gained significant ground! HD-SDI has been the common format of this however due to reliability issue a number of improved formats are battling it out from the big chinese manufacturers. HD-CVI and HD-TVI also known as turbo analogue.
You can get full HD picture quality just like IP CCTV but record it using a DVR similar to SD analogue. This technology sends a special digital signal which is capable of supporting this increased resolution via adirect connection for each camera. So there is no clever networking and IP addresses involved unlike IP
This has the following Pro's and cons:
- Superb resolution and clarity
- More affordable than IP
- Can be the most cost effective upgrade route when replacing an analogue system, so no need to rewire!
- Less flexibility than IP CCTV (
- Less camera choice (especially with the varying incompatible formats meaning you may have to stick with the one brand.