How to design and install (DIY) a new security camera system for your home or business.

In this article we explain what a CCTV system is (and why in the current environment you need one), how they are installed, and the bits and pieces you need to install and operate your new DIY Security Camera System.

Active Online assists home owners, tradies, and businesses every day in the design and installation management of new DIY CCTV systems. This includes selection of appropriate cameras and recorders and internal storage, the additional parts including cables and mounts you may require, cabinets and racks, monitors, and assistance with setup and configuration including remote access and fine tuning of advanced features.


Australian wiring rules govern who can install cabling in homes and commercial buildings and we recommend you check the rules in your state or teriitory.  We recommend you use a licenced electrician or data cabler for all cable runs. If you are self-managing your project you may setup and configure your own security system but if you are engaging an installer they should be licenced for security installation work.  This protects you in that the installer must follow legislated practices in the installation and is registered (including finger prints) on police databases in case there is an incident at a later date.  We provide the following information as educational material only and in no way advocate doing installation work if you are not licenced to do so. And now on to the educational material…

What is a CCTV System?

A Closed Circuit Television (CCTV) or video surveillance system is a system where a camera or group of cameras transmits video for recording or monitoring on a local wired or wireless network.  It may consist of cameras, a recorder, and monitors for viewing as well as connection to network infrastructure to route camera vision electronically to where it is to be viewed.

Typically CCTV is not publically broadcast and is used for private monitoring in security, surveillance or safety applications.

Why should I consider a DIY Security Camera System (CCTV) for my home or business?

CCTV or video surveillance provides a 24 / 7 watchful eye over your most valuable asset (your home) or your business.  Evidence is stored on a hard rive for later playback and can be extracted and supplied to law inforcement or insurance in the case of an event.

DIY Security Camera System for Residential CCTV

Typically cameras are installed externally for residential applications watching over access to your property.  You may install a camera in your garage, especially if there is an internal door to your home through the garage.  We would not recommend cameras in living areas in most cases due to privacy considerations – this may differ where there is a need to monitor a person with special needs.

Cameras can be configured to alert on motion, access to specific areas, or with AI functions – detection of human or vehicles.  These alerts can be scheduled and be remotely available on Smart Phone Apps or remote monitoring systems.

The main reason for CCTV in residential applications is for security and safety. Modern quality cameras can provide high resolution images necessary for law enforcement to identify trespassers and are usually a visual deterrent to those looking for an easy target.  Unfortunately CCTV won’t always deter desperate criminals as the fear of getting caught is sometimes less than the need to find valuables they can sell for money.  At least you will have the evidence to provide to police and insurance in the case of a robbery or home invasion.

DIY Security Camera System for Business or Commercial CCTV

CCTV for business or commercial applications includes many specialist applications listed below.  Cameras may be inside monitroing staff and customers or outside monitoring car parks, building entrances, equipment yards, farms and vinyards for example.
An example of CCTV camera applications includes: Automatic Number Plate Recognition, People Counting, Face Recognition, Thermal Detection, PTZ (Pan Tilt Zoom), Point of Sale Surveillance, Process Monitoring, Driver Monitoring, and Safety Surveillance.   These cameras may be used to monitor the number of peple within a defined area, or open gates for vehicles based on the number plate, or alert emergency systems to fire or temperature as just some examples of potential uses for CCTV.

Types of CCTV System installation

The types of systems (not brands or makes) refers to the way vision is transported to the recorder. All new systems are digital these days and tend to use cat5 or cat6 cable, wireless, or retrofit to coaxial cable.

Analog or connected by coaxial cable

Pre-existing systems were in most part analogue transported over coaxial cable.  The cable looks like black antenna cable and usually had a twist on and off style of connector at the camera and recorder end.  These systems had limited resolution similar to old analogue television.  It is still possible to buy systems which work over the same cables but they are generally digital in nature which provides higher definition images.  We supply HDCVI cameras which are High Definition Composite Video Interface cameras.  Other digital retrofit standards offered are HD-SDI, HD-TVI which are supported by recorders from different brands.
If you have good quality coaxial cable from a pre-existing CCTV system you have a good option to save cabling costs and retrofit HD-CVI cameras and recorder. Another option is to use ethernet over coaxial cable converters and install standard IP-PoE cameras.

Wireless CCTV

Wireless or Wi-Fi based CCTV tends to be used where cabling is difficult or where battery powered cameras are to be used.  All cameras require power to operate so either battery, cable, or solar power is required for these cameras.  Due to the need to transfer video across Wi-Fi these cameras are usually not available with as high resolution as a cabled camera.  The are also subject to interference and Wi-Fi congestion and require very good Wi-Fi network to operate effectively.  As most cameras on standard CCTV are up high on eaves or on poles near boundaries it may require implementation of a Wi-Fi mesh network or repeaters / extenders to ensure there is suitable Wi-Fi at the camera.

Cat5 / Cat6 cable

The majority of new systems will be utilise Cat5 / Cat6 cable to connect cameras to the recorder.  These systems use Internet Protocol for transport of data and the cameras are usually powered by Power Over Ethernet (PoE) using the same cable.

The cable allows for high definition video with no interference and a simple cable which can be purchased pre-terminated in standard lengths or supplied cut to length by a data cabler or electrician.

There are distance limitations with these cables which are easily overcome with mid-span switches or using special cameras and switches that use proprietry techniques to extend data and PoE on standard cable.

CCTV Cameras

CCTV surveillance cameras come in many different types. Typically there is the camera body which takes on suitable form for mounting the camera and enclsong the optical and electronic components.  Typical camera body types are bullet, dome, turret, PTZ and others.

Lens Type

Another distinguishing feature is the lens of the camera.  The lens may be:

  1. Fixed lens: the lens is fixed to allow a fixed field of view expressed in degrees (horizontal and vertical). These are known as monofocal and will typically be expressed in millimeters eg. 2.8 or 3.6, which is the focal length of the lens.  The smaller the value the wider the field of view.
  2. Varifocal: These are manually adjustable lenses which are set at the time of installation.
  3. Motorised Varifocal: the lens is electronically adjustable for zoom and focus. These are used to maximise the image on the sensor so that there is efficient use of the sensor.  Adjusting the zoom also adjust the field of view so that when you zoom in the field of view is narrow.  These cameras save money on installation as the camera can be mounted far away from the target and then zoomed once in place.

Other types of cameras include PTZ which are Pan Tilt Zoom cameras with the ability to be steered and zoomed remotely or even set to tour through preset positions and track objects when detected.  These are expensive cameras but can reduce the need for many cameras at the same site.

Panoramic cameras usually contain multiple cameras with the combined field of view of 180 degrees.

Night or Low Light Vision

Night vision is a desirable feature of CCTV cameras and may be provided through in-built Infra Red illuminators (the vision will appear as black and white), starlight sensors or very / ultra low light sensors that will display colour images with very low light levels, and intrusion type cameras which will use IR illuminators until triggered by AI and then switch on a white light as warning and for colour recording.  These last cameras may also flash alarm lights or sound a siren and are often capable of 2-way audio.

Camera Image Modes

Cameras often have to work in difficult lighting conditions and to compensate for lighting you will set the image mode of the camera.

  • Backlight Compensation (BLC) brings more clarity to dark areas of an image, particularly when bright light is shining from behind. This is useful when the image is mostly bright and there are areas which are difficult  to make out due to the bright back lighting.
  • Highlight Compensation (HLC) brings more clarity to light areas of an image, particularly when there is a bright light source such as a headlight or spotlight in the image. This is useful when the image is mostly dark e.g. capturing a cars number plate when its headights are on.
  • Wide Dynamic Range (WDR) brings balanced clarity to both light and dark parts of the image. through the use of 2 sensors and blending the 2 images. This is useful in most CCTV applications, but may not be available for older, cheaper or specialised cameras.
  • Digital Wide Dynamic Range (DWDR) uses software to replicate the effects of WDR, but doesn’t achieve the same quality as the real thing.

Camera AI and Intelligent Video

Many cameras are now equipped with the ability to recognise humans, vehicles, number plates, facial recognition, people counting, line crossing etc.  Setup and recognition of these triggers an event which may also trigger a recording, an alarm, a push notification etc.  These events also assist with searching through volumes of playback identifying in the timeline where these events took place.  Development in AI is accelerating and probably the most useful development of CCTV in recent times.

Modern cameras may also include a storage slot for microSD devices which provides edge recording of the single camera.  The playback of this video can be done remotely through an App or desktop program and enables surveillance and playback without needing a recorder and also provides a secondary source of playback video in case the recorder fails or the network to the recorder fails.

DORI – Detect-Observe-Recognise-Identify: A method to determine a cameras suitability

The DORI distance is a “general proximity” of distance which makes it easy to pinpoint the right camera for your needs. The DORI distance is calculated based on sensor specification and lab test result according to EN 62676-4 which defines the criteria for Detect, Observe, Recognize and Identify respectively.  In plain language it shows you the distance where the camera will detect, observe, recognise, or identify a person based on the cameras number of pixels and the field of view.

For example a 2MP or 1080p camera would have 1920 pixels across and if it had a 90 degree lens would provide enough pixels on the face area (250px /m) at 4.9 meters to allow identification.  The same camera would detect a person at 48.9m based on 25px /m.

For a motorised camera you can calculate the DORI based on the horizontal field of view when zoomed out and at full zoom.  You just need to know the horizontal field of view at both extents of the lens.

The DORI criteria is based on the number of pixels on the target (person) with a higher density of pixels as the criteria increases.  For example, a camera sensor is made of a small dots or pixels and the number of pixels is the camera resolution.  A 2MP camera has 2 million pixels and usually will be 1920 across and 1080 lines down. An 8MP camera will have 4 times as many pixels and therefore higher resolution.

The requirements for each of the distances is as follows:

Detect: 25px/m or 25 pixels per meter
Observe: 63px/m
Recognise: 125px/m
Identify: 250px/m

DORI makes it easier to choose a camera for your DIY Security Camera System if you know the distances to targets.  Generally you would choose a camera based on if identification or recognition of a person was required and select based on the stated distances.

We have a free DORI calculator you can acess here:  Free DORI Calculator – Active Online

CCTV Recorders

CCTV may be recorded locally on the camera using a microSD card (edge recording), or through streaming to a recording device.  Recording devices may be a Network Video Recorder (NVR), a Digital Video Recorder (DVR), Network Attached Storage (NAS), or upload to online storage through File Transport Protocol (FTP) or other means.

When designing your DIY Security Camera System it is important to consider how you intend to store and access video as evidence if needed after a security event.

Edge Recording

Many CCTV cameras have a built-in slot for microSD cards for local recording.  The camera usually has to be opened to access the card slot and there will be a maximum card size.  Edge storage allows you to nominate events or even full stream to be recorded on the card.  You can access the camera and playback stored video (usually the camera would be accessible over the network and not be connected to an NVR dedicated camera port).  Edge storage provides recording capability where an NVR or other storage is not available and also provides a backup of recorded video in the event the NVR or network fails (or the NVR is removed).  This type of storage does have a limited life in that microSD cards are rated to a finite number of read / writes.  Video is overwritten when the card is full which must be taken into account when calculating the length of the stored video.


A Network Video Recorder is a dedicated device designed to record video streamed over an IP network.  An NVR will record video streamed on the local LAN through its LAN port and also through dedicated ports provided for each camera.  These dedicated ports also power the camera using PoE and the same cable.  Each of these dedicated ports can only connect to a single camera and is the most common way of connecting IP cameras to a recorder.  Dedicated camera ports has an added benefit of keeping streaming traffic off your local network so you are not faced with latency issues for other network applications.

The NVR will usually be based on Linux Operating System stored as firmware with any installed hard drive being solely for the storage of video.

An NVR is best used for recording cameras from the same manufacturer to enable access to all camera and NVR features.  An NVR may be able to record the streaming video from another brand camera but may not access the other features including camera initiated events, camera control, and changes to camera setup and function.

An NVR may also have features allowing it to perform AI functions on an incoming stream.  AI is resource intensive and usually there is a trade off between AI and performance i.e. you may be limited to a set number of channels and channel resolution for AI due to the high workload required on the NVR.


A Digital Video Recorder receives video through coaxial cable connectors on the rear and converts it to digital for storage on an installed hard drive.  Modern DVRs can also record IP streams through their LAN port allowing for expansion as new IP cameras are added to the system.

Modern DVRs are able to record many different formats including analogue video and the HD version as well as the different digital formats – HD-CVI, HD-SDI, HD-TVI etc.

A DVR may have AI functionality as well which greatly enhances the event reporting and search functions when looking for incidents.  If connected to the internet there may be an App which allows monitoring, playback and push notifications.

The biggest noticeable difference between video on an NVR and DVR is that the DVR video will not be as smooth as the resolution increases.  There is a capacity limit to how much video can be sent down a coaxial cable and be decoded by the recorder.  The way this is processed is at a lower frame rate which represents as time steps between frames.


Network Attached Storage provides storage of streamed video on a network.  A basic NAS will record the incoming stream for playback and will come with surveillance management software and a limited number of camera licences.  Additional cameras will require the user to purchase additional camera licences for the NAS.

The main consideration for a NAS (beyond camera licences) is whether the main purpose of the NAS is for surveillance recording.  If this is the case then you should consider using surveillance grade hard drives in the NAS due to the predominantly write based nature of streaming video recording.  Surveillance grade hard drives are designed for heavy write activity 24/7 whereas standard data hard drives may not perform as expected or last as long.

If using a NAS you also need to consider the processing power and memory of the NAS.  Check the specifications around number of cameras, camera resolution, and frame rate to get a real idea of the processing power of the NAS (and don’t forget the number of camera licences).  If you add software for AI into the mix you need serious graphics processor / memory / CPU grunt for these activities.  Another area to consider is the bandwidth required for many camera streams on your LAN and through the network port of the NAS.

Accessories to a CCTV System

There are many accessories you can add to a DIY security camera system and we have listed the most basic below.

Camera Mounts

Camera mounts and junction boxes are used to match the camera body to the surface being mounted on and in some cases extend the camera into the the best location to capture the vision.  Junction boxes provide access for cables and add some clearance for plugs, conduit, connector water protection etc.

Camera mounts are usually specific to a camera type so that mounting holes line up correctly and the system remains weather resistant.  You may need mounts and junction boxes to mount cameras on poles or vertical walls or on locations where there is no cavity like the concrete ceiling in a carpark.  PTZ cameras may need parapet mounts to allow the camera to sit above the surveillance area and maximise the 360 degree pan of the PTZ camera.

Racks and Security Cabinets

A security surveillance system is great for storing evidence but what if the evidence is stolen?  Aside from edge storage or any storage online the local storage is susceptible to theft if the intruder wants to hide their tracks.  Security cabinets and storage racks can make that more difficult as well as tidy up the installation and reduce noise.

Monitors and Accessories

At very least you will most likely require a monitor to setup an NVR / DVR and having a local monitor with mouse allows the system to be standalone for setup and accessing vision on your recorder.  It is important to understand that the stored vision may be higher resolution than the monitor (or Smart Phone) that is being used to view it in which case the resolution will only be as good as the monitor.  For 4K resolution systems you require a 4K monitor or TV to see the vision in all its glory.  This includes cables and any devices used between the monitor and NVR such as extenders.

Some systems may have multiple monitors and there are multiple HDMI outputs on many recorders or you can use a HDMI splitter or even a PC accessing vision through a web interface.

If the system is connected to the internet you can also setup remote software to stream and playback video on site.  The system will most likely have an App for remote viewing video on Smart Phone as well.

PTZ Controller

A PTZ controller is a plugin keyboard / joystick device for managing multiple PTZ cameras on a network.  These are much easier to use than the on screen version found with most PTZ cameras and recorders.

System Security – NDAA and other matters

Any device connected to the internet is subject to hacking attempts. If you want to ensure you are not hacked, don’t connect to the internet.

Given that almost all users want the capability of remote monitoring / playback, push notifications etc then it is accepted that a connection to the internet is required.

Best practices should be followed which includes keeping firmware up to date and changing your complex passwords regularly.  Also refer to any security settings within the devices – some have firewall settings which are useful.

Another best practice in our view is to not place a camera overseeing areas where privacy is assumed – living areas, bathrooms, changing rooms etc.

NDAA – The National Defense Autorization Act is a USA specific act which bans the use of CCTV equipment that includes applications or components manufactured by specified Chinese companies and their affiliates.  This act is specifically for US Government based installations and there has been media coverage of equipment from some brands being removed from Government facilities in Australia.

We do have NDAA certified brands available for sale and you will pay more for these brands.  Is the cost worth it for a family home or low priority facility?  That is up to the buyer as only you know what is at stake if you are hacked by someone who is looking for opportunity or a State based actor.

DIY CCTV Surveillance System Design – Putting all together

This guide provides links and advice to find the equipment and assess its suitability to your design.  We will be expanding and growing this section as we find easier ways to qualify equipment for your design.

Checklist for DIY CCTV Design – camera placement

  1. Question 1 – Do I have existing cables in place and what type are they?  Can they be repurposed? Where does the other end go and will that suit my new recorder location?
  2. Installing cables for cameras in the ideal location can be the most challenging aspect of DIY CCTV Design.  It is a case of what comes first – where do I want cameras and why, and can I run a cable there.  If not, where can I run a cable and how do I cover the area I want with a single camera (or maybe 2 cameras)?  Remember that the camera cables either have to go to where the recorder is located or access the LAN in some way.
  3. What is the camera requirement? Is there a distance that I want to identify or recognise people or vehicles? Do I need a motorised lens to reach that distance from where the camera will be located?  How wide does the camera have to see to cover the area?
  4. Do I need night vision and how far do I want to see at night?

The questions above will help you plan the locations for cameras based on where it is possible to cable and the area you wish to cover.  There is a trade off between identifying / recognising someone and the area to cover.  This is because you may need a zoom lens to be able to achieve recognition at a certain distance and a zoom lens will narrow the horizontal field of view.  Overlapping fields of view prevents an intruder from avoiding detection but it can also be expensive resulting in many cameras.  A mix of cameras at entrances to identify intruders and long view cameras to detect intruders is the best mix.

Checklist for DIY CCTV Design – recorder selection

  1. What type of cameras am I recording – IP, HD-CVI?  This is required for the decoding of the camera signal.  It is possible to use Cat5 /6 or coaxial cable for any type of camera with the right converters.
  2. How many cameras do I wish to record?  Include video intercom as well if you want to record your front door or gate.
  3. How much storage do I need?  This will depend on how many cameras, the resolution of each camera, the encoding used on the video, and whether the cameras are constantly recorded or only when an event occurs.  Event based recording can miss recording so we would encourage continuous recording for that reason.
  4. Do I need high processing power for AI or intelligent processing?  The recorder specifications will outline the number of AI channels supported with each recorder.

If you are replacing an analog CCTV system consider using HD-CVI cameras and recorder.  Another option is to use the coaxial cable to carry IP using ethernet over coax converters.

Recorders generally write new recordings over the oldest recording so you will find you have a constant amount of recording you can search eg you may have 1 week of recordings before they are overwrite depending on how large the storage is in the recorder. Some recorders have multiple bays for hard drive storage – note that surveillance recorders require surveillance grade hard drives to cope with the constant activity.

Checklist for DIY CCTV Design – accessory selection

  1. Do I need mounts or junction boxes for selected cameras?  These will be brand specific.
  2. Do I need monitors for the recorder?
  3. Do I need prefabricated IP or coaxial cable for my installation?
  4. Do I need a security cabinet or rack for my project?
  5. Do I need edge storage for my cameras?
  6. Is there any other item required for my project?

Product Selector for DIY CCTV Systems

The listings below are to categories of products to start your research and design.  Each opens in a new window and you can return to this page at any time.  You can then add the various items to your cart for purchase.  If you want us to check your order first please select “Request a Quote” and don’t pay.  We can then look through the items you have selected and discuss with you before you purchase.