Security Cameras

The following information has been reproduced with permission from the book
‘Rural Living MANUAL‘ 2nd Edition by author Bernie Webb.

RURAL-Security-Cameras.pdf (374 KB)

After a potential intruder entered our property unannounced, we decided to install a security camera to continually watch and record ‘coming and goings’ at our front gate and its approach (Figure 1).  I am not going to detail all the ins & outs of Security Cameras here but merely mention a few points to consider before installing or having security cameras installed[1] at your property.

Quality

Generally, the more $$ you outlay the better the quality of the system.  A major reason for having a Security system is to identify who has been on your property. Details like frame rate[2], resolution[3], upload speeds[4] & adequate night vision[5] will all have an impact on whether a ‘person of interest’ can be identified or not. Although adequate resolution is very important, also understand that it is influenced by the quality of the lens amongst other things.

Storage

Obviously, you will need to store the recorded video (preferably ONVIF[6] video stream). Features like frame rate, resolution & length of time to keep recordings[7] will all affect the size of the storage required.  Each camera added to the system will multiply the amount of storage required, soon growing into a substantial storage space requirement (see box below).  If you don’t record everything at the Cameras highest rate, there is little reason to have purchased a quality camera!  Keep in mind, should you decide to store to the cloud (especially at higher resolution) that this will consume a considerable amount of your Internet Data quota.

CCTV camera storage calculation formula –

Storage Space (GB) = Bitrate (Kbps) * 1000/8 * 3600 * 24 * Cameras * Days/1000 000 000
If you have 3 cameras whose maximum bitrate is 1024 Kbps and want to record for 14 days nonstop before it is overwritten, according to the above formula, the required storage space: –

Ø  1024 * 1000/8 * 3600 * 24 * 3 * 14/1000 000 000 = 464.4864 GB (nearly half a terabyte!)

Power

Not only does each camera, transmit video, it also must be powered and some PTZ[8] (Pan-Tilt-Zoom) cameras need to be controlled as well. Although Wi-Fi[9] would seem the obvious choice to achieve this it is more susceptible to interference and a separate power supply is still required. Perhaps a better option is PoE[10] (Power over Ethernet). This is harder to install initially but would be far better in the long term.
PoE[11] run over a Cat 6[12] cable (up to 100m) can power the camera, collect the video stream and if required, control the camera.

A few more points to come to grips with; –

  • Bullet v Dome v Hidden v Turret cameras
  • Motion Detecting
  • Able to generate Motion Alerts
  • Accessible from the Internet
  • Some cameras can also capture audio as well as video
  • Wide Dynamic Range
  • DVR v NVR v Cloud v SD-Card
  • Choose a system that can synchronise its internal clock with the Internet.

I’m not doing all the work for you; either google these points or ask the installer/sales rep, who will be far more qualified than I to answer your questions (at least he/she should be).  My main aim here has been to give you an overview so that you have some idea what an installer/sales rep is talking about.

Any Useful Video Recording(s)

After your system is all up and running, should you have relevant video recordings that, for whatever reason, could be useful to the Police, don’t just hang on to them, give the police a copy.

[1] If paying someone to install your surveillance system, they must hold a Security Installer’s Licence – Class 2

[2] Frame Rate – Minimum 25 fps (frames per second) Industry standard 30 fps – also known as refresh rate.

[3] Resolution is measured in Megapixels (MP) – high resolution is considered 2MP or greater, 4K (8MP) recommended.

[4] The speed that your network or security system can upload recordings to be stored.

[5] IR (Infrared) – can see in complete “darkness”, usually measured by the distance that it can ‘see’.

[6] ONVIF (Open Network Video Interface Forum) – founded to standardize the IP-based surveillance camera industry

[7] 2 x weeks to a month or more?

[8] PTZ – Pan left & right (usually 360o), Tilt up & down, Zoom in & out – usually a dome style camera.

[9] Wi-Fi range – typically less than 50m

[10] PoE – Power over Ethernet also known as IP (Internet Protocol).

[11] Note: the ‘Switch’ that the PoE is plugged into must be a ‘PoE’ type switch.

[12] standardized 4x twisted pair cable for Ethernet – backwards compatible with Cat 5/5e.