Here are the answers to some of the common questions we receive from clients about IP CCTV systems. If you can’t find the answer to your question here please send us an email or call 0508 11 00 22, we’d be pleased to help.
You may see high definition CCTV called HD (high definition), IP, MP (megapixel) or network CCTV. They all refer to the same CCTV technology. This technology offers high resolution recording and playback for security footage on a network system.
How does a HD system provide such good images?
An IP CCTV camera ranges from 1.3 to 10 megapixels in resolution whereas even a high resolution standard analog security camera provides only around 0.4 megapixel resolution size. This makes the footage so much more useful for facial recognition, till monitoring, object search and more. You can see in the image below the difference in image size between an analogue image (CIF & 4CIF) and the various IP security camera options. The differences become very apparent if you attempt to enlarge or zoom in on an image as the lower resolution analog images will immediately pixilate.
What are the components of a megapixel IP CCTV system?
- IP security cameras
- An NVR (Network Video Recorder) which records and allows playback and search of the video footage
- A monitor for viewing the live and recorded footage -or can be viewed from PC, Mac, iphone, ipad or android device
- Network cabling
- PoE network switch to power the cameras
With an IP system each IP camera is wired to a network switch where it uses the existing network infrastructure (or, preferably a new network is built for the system) to take the video signal back to the NVR. IP CCTV cameras can also be integrated with a wireless network. This means expansion of the system is almost limitless and in many cases installation is less involved than with an equivalent analog CCTV system.
How much hard disk space do I need?
This will depend on several factors:
- How long do you want to keep recordings for? The industry standard is around one month but you or your insurers may have other requirements. If you are away from the business for periods longer than a month it is recommended that you extend the preset amount of time before the older video is over-written, allowing you to access footage recorded in your absence if necessary.
- How many CCTV cameras do you require? The more security cameras you have (and the higher the resolution of the cameras) the more hard drive space will be required to hit your target storage time.
- What frame rate do you want to record at? The recording rate of the CCTV camera will affect the amount of hard drive space used for a given amount of recording time. eg if you record in “real time” 25 frames per second (FPS) you will use twice as much hard disk space per hour of recording than if you recorded at 12.5 FPS. While higher frame rates may sound better, unless you have a fast moving subject in most cases 8 FPS is fine.
- Do you need full time recording or motion activated? In most cases motion activated recording is the most efficient way to go as there is no point recording when nothing is changing in the picture.
Once you have thought about the points above contact us and we’ll work out the storage space you require.
Will a higher definition camera always deliver a better picture?
No, other factors come into choosing the correct camera for any given situation. As a rule of thumb higher megapixel cameras generally do not perform as well as lower megapixel security cameras or sometimes even analogue CCTV cameras in low light conditions.
We have conducted tests with a leading brand 1.3MP IP CCTV camera and a 700TVL analog security camera and DVR in subdued lighting (similar to most retail shops) at night and the analog camera actually provided a much more useful picture. The 1.3MP camera became noisy due to the low light level. During the day the 1.3MP however gave a great picture.
If you want a high resolution security camera for use at night, it is important to choose an IP camera with a low illumination image sensor and features such as 3D digital noise reduction. 3D digital picture noise reduction dramatically reduce the picture noise (which shows as static on screen) during low light conditions. Features such as Smart IR and the latest EXIR illuminators also make a big difference to night time performance.
How does network bandwidth affect camera selection?
You should always consider band width requirements especially if you are connecting the camera over existing network infrastructure or want to solely view over the internet. For example if you have a situation where you will only use the camera to view live images over the internet there is no point installing a 5MP security camera as it will require around 8 mega bits per second to stream video at 8 frames per second. Unless you have a fibre internet connection your upload speed will not come close to 8Mbps so a lower spec camera would be more appropriate.
I want a single security camera, do I need to go to the expense of buying a multi channel NVR or recorder?
Not necessarily. We have IP CCTV cameras which can record onto a built in SD card. However there are limitations in using this type of system:
- Limited recording time – the amount of footage able to be recorded before the SD card is full and starts overwriting is limited to the maximum size of SD card compatible with the camera – this is typically one or two weeks max depending on the recording resolution and frame rate.
- Long term life of an SD card – SD cards have a limited number of times they can be written to which can mean the SD card could fail. Unless you are regularly checking the camera and recordings you may not know it is not recording until it is too late. Using an NVR to record to a hard drive ensures the system is working properly as the NVR will sound an alarm if something goes wrong.
- Data security – if the camera is stolen with the SD card on board you will also lose any recordings relating to the theft. Using a separate NVR to record video is much safer.
Some IP security cameras come with free recording software for your PC. Do you support this type of set up?
No we don’t. While this may work okay on your PC we cannot guarantee the integrity of the system using an existing PC. Factors such as the computer’s hard drive not being a surveillance spec drive designed to be constantly written to can cause problems.
The bandwidth a high resolution camera uses can be too much for some home PCs especially if they are also used for other tasks. If the PC crashes it will stop recording.