CCTV Tips and Tricks

What's the Difference In Picture Quality

You will note the resolution or amount of pixels available for the different cameras below. I have noticed a lot of camera suppliers in the market stating that their cameras are a particular type say 960H then when you look at the specification data sheet, it says under the resolution tab that they supply 720 x 494 not 976 x 582 as it should state for 960H cameras. It is critical to go off the specs for the cameras and DVR specifications when selecting which CCTV system to buy. 

   Analogue Cameras        960H Cameras               720P HD Cameras        1080P HD Cameras

    Resolution 720 x 494                     Resolution 976 x 582                     Resolution 1280 x 720                 Resolution 1920 x 1080

Whats the Difference In Picture Quality




Why have a Matched System

The most important thing to remember when designing a Surveillance camera system is that output picture quality follows the lowest devices stated resolution. To give an example of this if you install analogue 540TVL cameras with an HD-SDI 1080P digital video recorder, and HD 1080P monitor the resulting picture will be a standard analogue resolution, not High Definition. All CCTV parts in this system would need to be HD-SDI to achieve a High Definition picture.

Just because a camera specifies a resolution of 750TVL or 540TVL doesn’t mean that it will provide that image quality. These resolution values come from the lens type. Most cameras have Sony lenses installed in them, but it’s up to the manufacturers to design and test the electronic circuitry that supports the lens. In other words, the cameras electronic circuitry significantly affects the resulting picture output. I have seen high-resolution cameras provide poor image quality as a general rule price is a good guide to go on.

Learn About Real Time Playback

About Digital Video Recorders and Network Video Recorders. They have to record and playback in real time. Some manufacturers state that the Recorders are real time, but they only view real time not record real time. The resulting playback footage stops then start again but pieces of footage were missing, and you can’t ascertain what happened in the stop parts of the playback. I can remember going to an RSL club to extract footage of a bag snatch for the police. Due to a poor recording system all the footage showed was the offender walking to a lady sitting at a poker machine then he’s back as he walked away the crucial point of his hand on the bag wasn't there, and the footage had no value to the police.

What Height should I mount my Cameras?

I get a lot of people asking for a quote to have cameras installed under the eaves on the second story of their two story house. My reply is that the cameras won’t give good pictures up there. The cameras will pick up the crown of people's heads as they are looking down at such an angle. Cameras need to be installed at their stated installation height to achieve the desired site surveillance.

Do I want to Remote View my Cameras?

If you want to remote view your cameras off-site, you need to double check that your internet service provider can supply a “Static Public IP Address” for your broadband service. Without this, your public IP address will keep changing resulting in the remote viewing App not working as this public IP address needs to be entered in the application to provide the connection to your ISP.

If your ISP can only provide a DHCP Public IP address, It is possible to get around this by using a DNS service. But both the DVR and remote viewing app needs to support DNS configuration. Plus it’s harder to configure and, in my opinion, less reliable as the DNS server has to check your ISP public IP address and convert that to a domain name for the remote viewing to work. What I have found is when your DHCP public IP changes it takes time for the DNS server to update its records. In this period, your remote viewing won’t work. Another issue is that the free DNS services usually are a little unreliable usually located overseas in Asia and if that server goes down your remote viewing won’t work.

How To Set Up Camera Remote Monitoring through a Digital Video Recorder

Before we start, I just want to mention how frustrating it can be to set up remote viewing. You have to have some idea of computer networking or have a lot of time to research how to set it up to be successful. I have only noted the basics of it below, but there are just so many different parameters and issues that may arise to give a specific procedure. For starters, there are so many different broadband routers that have different programming options. Although rare some routers just don't do it, and you have to buy a new one. But the main issue I come across time and time again with customers is to check everything you have typed into the field tabs to set it up. It only takes one wrong letter case in a password or username to bring the deal undone. Another huge tip I can give is to set up the whole remote viewing setup locally first. In other words, connect your smartphone to the router's Wi-Fi network and put the IP address of the DVR or NVR in the Remote Viewing App. If it works the set up is ok, it's just the routers configuration that allows you to come through the routers gateway to connect to the DVR or NVR that's got issues.

Some other things you need to know is the DVR/NVR requires programming with a static IP address on the local network. When programming a static IP, your router has to either exclude it from its DHCP server or the router has to be always configured to give the DVR/NVR the same address all the time. Also once connected to the router the NVR/DVR has to have its address set to static under network tab in the machines configuration software.

Another important factor is the routers port forwarding has to be enabled to port forward the DVR/NVR's ports to the machines static IP address. This configuration is in the router, but the configuration is just too varied to give you any help. The best hint I can give is to look up your router's installation manual on the internet.

Lastly, you need to know your Public IP Address to put into the app so you can remote view off site through the 3G/4G mobile networks. To find out this open Google on a computer that's connected to your home or business broadband router and type into the search bar "WHAT IS MY PUBLIC IP" Google will return the address for you. The returned address resides in the app.

And finally, I would recommend you do this to check that you do have a static public IP address. Reboot your router and perform the search on Google again if your public IP address has changed you don't have a static Internet Protocol Address, and you need to contact your Internet Service, Provider.



Learn about Infrared Night Vision

I have seen different cameras with the same stated IR specifications perform differently at night. I have found the price is usually a good line to follow when deciding which camera shows the best about Infrared night vision. But I should note that IR cameras require some form of lighting to perform to their full potential at night. Moonlight or streetlights are usually enough, but if it is entirely dark, most cameras struggle to provide a useful picture.

What kind of Camera lenses do I need?

Consider what areas of the property you want to cover with surveillance and match cameras with lens types that suit your plan. To give an example of this, you may wish to provide coverage of room inside your house which will only need a camera with a fixed 3mm lens. Unless the room is extremely long and you wanted to zoom in on a door at the very end. It would require a camera with an approx 3mm to 12mm variable lens that you can adjust to zoom in on the door. Maybe you need to cover an entry gate to the property that is 50 metres from the house. For this, you need to fit a camera with a variable lens up to 22mm if the gate is further maybe a camera with a variable lens to 50mm and soon the further away the area is the higher the lens goes, and the more expensive the cameras and lenses get. There are plenty of Lens Calculators available online if you want to get down to exactly matching a lens to your specific distance requirements. See this lens simulator to show the difference between lens lengths

http://polarisusa.com/lens-calculator