The DVR Buyers Guide
The DVR (Digital Video Recorder) is the heart of your CCTV Surveillance system. The DVR records and manages the cameras. This is a step by step guide to follow when buying any CCTV Digital Video Recorder. There are a number of important decisions to consider. This guide aims to keep you well informed when making these decisions.
The most important things to look for when purchasing a CCTV digital video recorder.
When you view live CCTV images that are produced via your DVR and displayed on your monitor the images will usually be very clear. However when it comes to recording those images the quality can diminish due to the resolution settings of the DVR. There are three industry standard resolutions these are as follows;
D1 or 4CIF as it is also known is the highest analogue recording resolution. It is advisable to use this setting on your DVR if you require images which provide the most clarity.
Half D1 or 2CIF is a medium resolution an usually recommended as it provides good quality images but requires less storage capacity than D1 resolution.
CIF is the lowest resolution which will provide you with low quality images but will maximize the storage capacity of your DVR.
How many cameras are going to be in operation?
The number of channels i.e. video input channels a DVR has determines how many cameras you can operate from that DVR. Typically DVR's have 1 Channel, 4 Channel, 8 Channel, 16 Channels, 32 Channels and 64 Channels depending on which model you have purchased or are going to purchase. A DVR with 4 channels will operate up to 4 cameras but no more. A DVR with 8 channels will operate up to 8 cameras but no more and so on.
Will your surveillance system require you to take audio recordings?
If the answer to this question is Yes! Then you will need a DVR with at least one audio input. The sound can then be relayed back to the DVR via an audio cable from an audio device or a CCTV camera with built in audio.
What does FPS stand for?
FPS is an abbreviation for Frames Per Second. A DVR's recording rate is measured using this format. For example if a 4 channel DVR records 4 cameras and has a recording rate of 100FPS that means each camera will record at 25FPS. That's 100FPS divided by 4 Cameras = 25FPS. This is the best recording rate you can achieve from any DVR as it is said to be Real Time recording. A frame can be best described as a picture. The more pictures in a second the better quality the video footage. If your DVR only recorded 5FPS then your image would be jumpy and not as finer quality as 25FPS. Government guidance states that the recommended minimum frame rate required for reliable evidence is 5FPS. We at DTS Digital recommend you do not fall below 12FPS when setting up your DVR as this will give you very good quality images.
How long do you need your DVR to record for?
Our own range of DVR's can be left to record for months without been touched. The DVR will simply over write old footage with new footage as soon as the HDD (Hard Disk Drive)is full depending on the size of the HDD installed, the number of cameras in operation and the Frame rate the DVR is set to use. The higher the frame rate the greater the disk drive space required to record the footage but the better quality the recorded images will be. Its all about finding the happy medium. You do not want your footage to be poor quality. However you do not want to shorten your recoding time to a point where it is quickly over written. You can find the various recording times of all our DVR's in each products more info page.
What is compression rate and is it really that important?
The short answer to this is Yes! The compression rate is a major concern when purchasing your DVR as it will directly affect the amount off HDD space your recorded footage will use up when stored. Most of the DVR's in our range use H264 compression technology. This is the very latest in compression technology and can give you up to five times more recoding than old fashioned JPEG DVR's and twice as much as MPEG DVR's. Read More About H264....Click Here
How many monitors are you connecting to the DVR?
Most DVR's will allow connection of at least one monitor either via a VGA output connection like your PC monitor uses or via a composite video BNC output connection like a standard LCD TV uses. Either way the monitor will need a separate power supply to the DVR however most monitors are supplied with a regulated PSU so you will not need to purchase one separately. Many of our DVR's allow you to connect a VGA monitor and two additional composite video monitors which means you can have multiple monitors displaying images from one DVR.
Would you like to operate your cameras and view recordings from another location as well as where the DVR is sited?
If so you will need a network digital video recorder (NDVR) or an internet ready DVR as they are also known. This would be useful for say a shop owner who needed to keep an eye on his business even when at home. All our DVR's excl. The Simply Smart DVR have this facility. The DVR has to be connected to an internet router that has a broadband internet connection and a static IP address. The router then needs to be configured for port forwarding. Once all this is setup correctly at the DVR's location. The correct procedure needs to be followed at the remote location. Our DVR's come with software that has to be installed on your remote PC which will allow you to connect to your DVR over a broadband connection after you have placed the correct IP address and gateway address in the necessary fields . There is more guidance on this in the instruction manuals that come with each DVR.
How would you like to backup any recorded footage that you may required to show in court?
Backup Via A DVD/CD Writer- If your DVR comes with a built in DVD/CD writer or you are able to connect one via a USB cable then making backups is straightforward. On our DVR's you would simply place a CD or DVD into the CD/DVD drive, select your file(s) and format and the DVR would write them to the disk. The disk could then easily played on any PC. In our experience this method is preferred by the police as there is no risk of viruses being transferred as there is with a USB stick.
Backup Via A USB Stick- If your DVR is supplied with a USB backup facility then you would be able to obtain backups in the same way detailed above except by using a USB stick or memory stick as they are often referred to instead of a CD/DVD.
Local or Remote Backup- If your DVR is a network DVR and you have set it up on a LAN (Local Area Network) or a WAN (Wide Area Network) i.e. over a broadband internet connection. Then you will be able to make backups using a PC that is on the same network or that can access the DVR remotely i.e. from another location via the internet.