ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How to design your own digital surveillance system

Updated on December 31, 2013

Digital Surveillance System: An Overview

Need of Digital Surveillance System

There is no better proof of an event or incidence that has been seen by one's eye. That's why people say "You have to see it to believe". Unfortunately, not enough research has been done on paranormal activities helping us to be able to be virtually present anywhere at the place of our choice. There comes the advantage of today's technology: "An electronic Eye", i.e. the concept of digital surveillance. Although, there are many applications of digital surveillance, we will be primarily discussing about its security application.

How Digital surveillance compliments Alarm system

Almost all of us have Alarm panels installed in our premises to prevent an unwanted intruder. Also, most of these alarm panels are connected to alarm monitoring companies, by means of telephone lines or some kind of internet connection. This connection triggers an alarm at the monitoring company when an unwanted intrusion takes place in the protected premises. Basic purpose of doing this is that, one responsible person / company should be aware of an alarm generated by an unwanted intruder and consequently take action on that. Main problem here remains the delay between, alarm generated, alarm communicated and action taken, because of geographical distance between the protected premises and the monitoring company. This delay goes as an advantage to the intruder. All professional thieves now know that there is an average delay of approximately twenty minutes between the alarm generated and action force from the monitoring company to reach the premises. And these thieves take advantage of this delay. Just imagine a scenario where alarm is generated and monitoring company is able to remotely view your premises and record the event along with sending an action force to the premises. Catching of thieves will become so easy. This concept is nothing new, but basic aim of this article is that you can implement this system yourself at your premises without spending huge amount of dollars.

Home Automation

Another off-shoot of this system is Home automation, as now you have a bi-directional communication / control of your premises in view of exchange of information, e.g. you are on vacation and you don’t want outsiders to know that nobody is in house for 10-15 days. You may occasionally hop into a internet café, log into your home computer, select a light switch on the screen and click it “ON” and the your light point in the living room is “ON” or turn on the TV. Of course home automation is not our subject of discussion today and you may click below if you need further information. You may write to us also and we may help you in implementing this further.

Home automation systems.

Be creative and try to build your own home automation system. It will not only make your home more comfortable but will improve safety & security and save energy.

Wide angle vs Tele angle
Wide angle vs Tele angle

Lens Selection

Focal length of the Lens

Type of lens that you select for your camera, decides what kind of angle i.e. what kind of coverage you are going to get from your camera. Focal length of the camera is the factor which decides the angle of the view of camera. Larger focal length will provide smaller angle of view and hence bigger the size of the object on screen. This is true vice versa also. This is illustrated by the fig. below.

Above figure shows that if the lens’s focal length is large an object will cover most of the TV screen making it look big but the angle of view will be smaller. Similarly, if the lens’s focal length is small an object will cover small part of the TV screen making it look small but the angle of view will be larger.

Ambient and varying light conditions

Second criteria that requires the right lens collection is the ambient light condition. If the camera is out door, obviously the light condition will vary during the day and hence the picture quality will vary. E.g. when the sun comes to an angle where it comes right in front of the camera, camera will hardly be able to see anything. It is like shooting a picture from your still camera looking towards the sun. Even if you want to shoot a picture looking towards a bright light source, you will keep the shutter of your camera closed as much as possible. It’s the same thing in this scenario. But here we call it opening or closing of iris instead of shutter.

There are two types of Lenses available:

1) Manual iris

2) Auto iris

As the name suggests, If the camera is installed in such a way that it is required to look towards a brightly lit area or to be precise, camera has to look towards the light source, we can select a manual iris lens and adjust it to this light condition. This is when the light condition is not varying.

If the light condition is varying like sun light, auto iris will be the right choice where the closing and opening of iris is automatically adjusted based on light condition.

All cameras don’t support auto iris lens. So we must ensure that the camera that we are using can be connected with auto iris lens. There are 2 types of auto iris lens available:

1) DC signal driven

2) Video signal driven

You must check the camera as to what kind (or both) of signal the camera provides and select the lens accordingly.

Lastly, there are two types of camera mounting standard available: ‘C’ mount and ‘CS’ mount.

Just be sure that your camera and lens are compatible with respect to their mount standard.

Manual and motorized Zoom Lens

Earlier we saw how the appearance of the scene varies with the type of lens used with respect to its focal length. Lenses are available where this focal length is variable by means of a knob and the focal length can be set to a desired setting.

This can be manual or motorized. With motorized zoom lens it is possible to focus on an object by a press of a button or click of a mouse. We will discuss about it in detail when we talk about PTZ (pan tilt zoom) camera and digital video recorders.

Camera Selection

Types of cameras: CMOS and CCD

There are mainly two types of security cameras available CMOS (complementary metal oxide semiconductor) and CCD (Charged coupled devices). Both have got their own advantages and disadvantages and it is not correct to say that one is better than the other.

Electronically, CMOS cameras consume less power but the images produced by them are slightly less sharp than CCD, not because it cannot be made sharper but making them sharper is more expensive and the manufacturers are trying to cash on its cheaper cost and miniaturization. So CMOS cameras are more useful where less power is to be consumed and miniaturization of camera is required. On the other hand, CCD technology is more suitable when acquiring sharp picture is important where it can be made with less complex manufacturing process. Hence in general CMOS cameras are less expensive than CCD cameras. Ultimately both these types of camera give out a signal known as 1V peak to peak composite video signal. And as long as display device (TV, monitors, DVRs etc.) can accept this signal we need not worry about the technology how this signal is achieved.

Selection criteria with respect to resolution and lens

Second most important thing about a camera to be decided is its resolution. They are available like 330 TV lines, 420 TV Lines, 540 TV Lines and so on. Obviously, higher the resolution, costlier the camera. Resolution may be interpreted as the number of dots (also known as pixels) that can be uniquely displayed on the TV screen. So, more the number of dots better will be the quality of picture.

Another point that needs to be decided is, camera's sensitivity to light that is measured in terms of "Lux". Lesser the value of lux, better the camera will be able to view in low light condition. It is specified as 0.1 lux, 0.5lux etc. Since, it easier for black and white cameras to see with good resolution in low light conditions, many manufacturers design cameras in such a way that they show color images in good light conditions but turn black and white in low light conditions. Scene illumination is measured in Foot-candles (FTCD).

PTZ (Pan Tilt Zoom) Camera:

This is very intelligent mechanical-electronics integration, giving very advantageous results. Camera is mounted on a dual motor platform which is controlled by 2 motors, one for horizontal movements (panning) and the other for vertical movements (tilting). These motors are controlled electronically from the control room helping us change the direction and hence the angle of camera. Normally tilt angle is available from 0-90 deg. And pan angle is available from 0-355 deg.

Similarly, camera is provided with a motorized zoom lens by which we can focus on an object and have full control on lens from lower focal length to larger focal length. Range of focal length that a lens can provide varies from lens to lens and is the main factor deciding the price of the lens.

This whole unit is controlled by a micro-controller device which has many advantages. Firstly, instead of controlling all these functions by individual wires, serial differential communication protocols (like RS485 or RS442) are used so that 2 pair twisted or 1 pair twisted cables are sufficient to be laid for all the functions. Another major advantage being, it makes the whole unit intelligent and hence it is possible to create presets i.e. create a few points for PTZ camera and so that the camera always follow those points at a defined interval. E.g. first point may be far end of the gate, then turn by 45 deg. And zoom on an internal door and so on. PTZ cameras are specified for this feature as 64 presets or 128 presets etc. 64 presets means, 64 such points may be programmed.

Since these units now have become intelligent, protocols between PTZ cameras and the control room have to match. These days, Digital video recorders specify the make and models of cameras that can be controlled by the DVR. In case your DVR doesn’t specify a particular model that you are going to use, very often these cameras come with their own keyboards for configuring as well as controlling the cameras.

IP (Network) Cameras:

So far we discussed about cameras which give 1V p-p Composite video signal as final output. Expansion of these cameras is IP or network cameras where video to TCP-IP conversion is implemented within the camera and hence these cameras can be directly connected to an Ethernet switch. They are designed to act as video network servers. Just provide them with an IP address suitable for your network and they are ready to be used on your standard computer. Software are available to add DVR capabilities for these cameras.

These cameras are nothing but a video network server built into a standard camera.

IP Camera with SD RAM and pan and tilt
IP Camera with SD RAM and pan and tilt

A new innovation in IP Cameras

IP Cameras with SD RAM and Bi-directional Audio

With time innovative companies keep coming with new ideas. Recently many companies have revolutionized the concept of IP cameras by adding SD RAM and WiFi features in them. You don't need to connect these cameras to any DVR and the recording takes place in their inbuilt SD RAM. You may view the recorded video footage either through your laptop via WiFi or using smartphones. Not only that but you can pan or tilt these cameras by giving commands either through your browser or through your smartphone.

Cable Selection

Mostly co-axial cables are used for video signals of these cameras which are available in various standards like RG59, RG6, RG11 etc. you need to select a cable mainly based on the distance that the cable is going to cover. RG59 is suitable up to 100 mtrs. and RG11 can go up to 800 mtrs. These cables are basically classified with respect to the signal loss that takes place within the cable as they travel to a particular distance and their characteristic impedance. E.g. it is 75 ohms in RG59 and 50 ohms in RG11.

Latest development in this field is to use standard network cable CAT5 instead of co-axial cable by means of using a “BALUN” (balance-unbalanced load). Using CAT5 cable for video application becomes very useful in today’s environment where structured cable is gaining too much importance. (Of course topic of structured cabling is beyond the scope of this discussion, but we can understand the advantage of using CAT5 cable for video application)

Power Supply

There is no hard and fast rule as to what value of power supply a camera should have. Various manufacturers use different voltage for different models. Most common being 12V DC. But 24V DC and 24V AC are also being used as standards.

Similarly current requirement also varies from model to model. As we discussed earlier, since CMOS camera consume less power, they are available with power consumption as low as 50 M.amps at 12VDC.

Power cable termination on camera is normally through a DC2.1mm plug but again there is no hard and fast rule about it.

It is normally recommended to use regulated linear power supply rather than SMPS power supply as linear power supplies are cleaner especially in view of tiny voltage ripples.

Digital video recorder: Geovision
Digital video recorder: Geovision

Digital Video Recorders

Finally we have reached to the heart of the digital surveillance system, i.e. digital video recorder. Mainly in the market, 2 types of systems are available. Stand alone DVR and the PC based ones. Selecting a DVR on this criterion is actually a matter of choice. Stand alone DVRs are meant for just this application and are dedicated for surveillance system where as PC based DVRs are available either as PCI cards or USB based. Of course USB based DVR have their own limitations because of speed restriction on USB port.

Whether the DVR is stand alone or PC based, their selection criterion is same. Some of the main features that we need to go through before deciding a DVR are:

· Frame rate: If the DVR under consideration is 4 channels DVR and the frame rate is 20 FPS (frames per second), then each camera will get 20 /4=5 FPS. This will not be real time but just sufficient for standard security application. But the same FPS of 20 will be unusable for 16 Channel DVR as per camera FPS will be 20 / 16.

· Again, DVR specs. Should also mention whether this FPS is only for displaying camera pictures or also for recording. It may be the case that display FPS is more than the recorded FPS. In that case, although you will see a better display but the recorded picture might be quite broken one.

· You might be using a high resolution camera but if your DVR doesn't support high resolution then actually you are wasting your money on having high resolution and hence highly priced camera. Video image resolution are normally available as 320X280, 640X420 etc.

· Motion detection sensitivity: How sensitive is the DVR, to detect motion. This becomes very important when DVR has to record in an event of motion.

· Masking of a part of screen: Whether it is possible to mask / unmask a part of the screen, so that motion in that part is ignored by the DVR.

· User friendliness of overall use of software, especially playback features. How fast you can find an event of interest will depend on whether play back search scheme of the DVR is effectively made or not.

· Another important point to consider is whether the DVR uses hardware video compression technique or the software video compression technique. Hardware technique is more efficient and at the same time costlier.

· Password protection: Normally good software will have multi level password where the administrator should be able to configure various users with defined level of authority.

· What kind of networking features it provides. TCP/IP has its advantages that it is more efficient but web server concept has the advantage that it doesn't require software at the remote end but it is relatively slow.

Remote Watch:

Any DVR that supports TVP/IP or web server based networking can be viewed over LAN or Internet or Intranet.

Firstly, the DVR needs to be configured for fixed IP address which will be decided by your network. Once the IP is defined, you should be able to view the cameras / recorded pictures over the LAN just by typing IP address of DVR in the address bar of your internet explorer (In case of video web server) or by running a special software application provided by DVR (In case of TCP/IP application)

To view it over internet, your router on the network is to be told to communicate with DVR whenever a valid attempt is made on a particular port number. This port number is configured at the DVR end. If we define that port 1000 is for video images in DVR software, then router has to be configured so that all the data on port 1000 should be directed to the DVR IP address.

Almost all the routers have this facility and they are known as different names like, pin holing, port forwarding or creating virtual server etc.

Dont forget to browse thru these incrideble products

Amazon has some great products to build your own digital surveillance system.

Digital surveillance and point of sale solutions

We are a Wellington, New Zealand based company incorporated in 2002. We provided digital surveillance, Access Control and Point Of Sale products and have vast experience in executing turnkey projects in the field of electronics security, Point Of Sale solutions and IT Support.

VideoSecu 100ft HD Pre-made All-in-One Video Security Camera Cable Power Extension Wire Cord with BNC RCA Connectors for 720P 960P 960H CCTV Surveillance DVR System A1E
VideoSecu 100ft HD Pre-made All-in-One Video Security Camera Cable Power Extension Wire Cord with BNC RCA Connectors for 720P 960P 960H CCTV Surveillance DVR System A1E

Use with Closed Circuit Television (CCTV) applications and security camera components. This pre-terminated CCTV cable is perfect for transmitting video and power. Simplify the installation of surveillance systems by using one cable to carry video and power. Now, it's easier than ever to mount your camera just about anywhere you would like.

SE FC9955 Dummy Sensor Security Camera
SE FC9955 Dummy Sensor Security Camera

This camera is the ultimate crime deterrent. It features a motion detecting sensor that makes it appear to work as an actual security camera! A light will come on when the sensor is activated. No wiring needed. Requires 2 AA batteries (not included). Gift boxed.

VideoSecu Fake Dummy Imitation Dome Security Camera with Flashing Light LED Cost-effective Security CCTV Simulated Dome Camera 3PZ
VideoSecu Fake Dummy Imitation Dome Security Camera with Flashing Light LED Cost-effective Security CCTV Simulated Dome Camera 3PZ

This dummy camera is VideoSecu brand.This phony dome camera provides an effective and economical way to decrease and eliminate criminal activities, e.g. theft, robbery, break-ins, shoplifting by intimidating the criminals, giving them the illusion that they are being watched and recorded. When placed in your home or business, even the most sophisticated criminals will think the premises are guarded by high-tech surveillance. The dummy camera which is designed for quick and simple installation gives a feeling of security without the high cost of installing and maintaining a real system. The flashing light LED makes this dummy camera looks like an operating actual security camera. Additionally, it is an excellent deterrent for thieves, easily mounted anywhere on the ceiling or wall under entrances hallways indoors or outdoors.

UniquExceptional UDC6 Outdoor Dome Fake Security Camera with BLINKING LIGHT
UniquExceptional UDC6 Outdoor Dome Fake Security Camera with BLINKING LIGHT

Now you can deter robbery, theft, and vandalism without the high cost of a real security camera. When placed in your home or business, even the most sophisticated criminals will think the premise is guarded by a high-tech surveillance system and go in search of an easier target. In fact, these surveillance cameras have been modified into a "dummy" or fake security camera. This unit does contain a continuous flashing light. The camera features a fully adjustable mounting bracket that will let you install the camera quickly and easily using the included stainless steel screws. The camera requires 2 AA batteries that are not included. Dimensions : (refer to picture with dimensions) The conversions are as follows: 94mm = 3.75 inches, 100mm = 4 inches, 56mm = 2.25 inches, 152mm = 6 inches, 130mm = 5 inches.


My security camera recorded this video during a storm in wellington

Our New Range of Cameras

We have just received these analog and IP cameras. Please watch this video and email us if you have any query.

Pan Tilt IP camera
Pan Tilt IP camera

We just refurbished our website

Along with the arrival of new security cameras we have updated our website drastically.

Please click here to go through our new website.

Check This Range of IP Cameras from Geovision

Geovision Web server Config.
Geovision Web server Config.

Geovision Web server and Team Viewer

Geovision digital video recorder software with active web server and team viewer on the same machine has always created problem for me. So today I decided to test it thoroughly.

If Geovision's HTTP server is kept as default i.e. 80 and team viewer is installed, connectivity to web server outside the LAN will not give any problem but if you try to connect the server within the LAN using LAN IP address, Team viewer will block it. I tried it today.

Also, it will be more effective to use remote desktop provided by Geovision instead of using a third party remote desktop like team viewer etc. for seam less operation of Geovision.


    0 of 8192 characters used
    Post Comment

    • msnz profile imageAUTHOR


      5 years ago

      @matthews12: You are right. I still find those mirrors in a few shops in Wellington. Thanks for reading my lens.

    • profile image


      5 years ago

      What security measures did shops have before security cameras were invented?

      It must have been so easy to shop lift before security cameras were invented...They had these big mirrors that reflect a wide angle. They're usually placed in corners and blind spots. This way, you can just look at the mirrors and see your whole shop.


    • msnz profile imageAUTHOR


      6 years ago

      @DanSecurityGuru: Normally I advise to go for wireless camera only if cabling is impossible. However, if you have decided to go for wire less, select the one which does not have a frequency of 2.4Ghz (Most of the devices work on this frequency causing more interference). Select a different frequency. e.g. the following camera works on 5.8 Ghz

      Else go for wireless IP camera. There frequency modulation is better preventing interference.

      Do not hesitate to contact me if you get stuck in doing this DIY. I may help. Good luck.

    • profile image


      6 years ago

      I enjoyed the lens. You have some great information here that I'm using to design my own security camera system.

      I want to go with something wireless that I can monitor anywhere from a computer or phone. My home is older and I prefer not to wire something through the walls. Do you have any ideas?

    • msnz profile imageAUTHOR


      6 years ago

      @ivycater: You need to decide on the following factors:

      1) How many camera you need indoor or out door.

      2) If out door, go for vandal resistant low light camera with auti iris lens.

      3) Take only CCD camera with sony chip.

      4) Prefer PC based recorder. I will recommend geovision.

      5) For more details check our site

    • profile image


      6 years ago

      Great lens

      I'm considering to purchaseSurveillance Equipments or Security DVR

      Could you give me some advise?


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)