CCTV (closed-circuit television) is a TV system in which signals are not publicly distributed but are monitored, primarily for surveillance and security purposes. CCTV relies on strategic placement of cameras and private observation of the camera's input on monitors.
Video surveillance offers endless benefits to the everyday business owner. Not only do they protect against outside break-ins and burglaries, vandalism and liability. They also play a critical role in sustaining your business, monitoring customer and employee behaviour and making it a safer place to work. Simply put, purchasing a few reliable surveillance cameras for your business security can yield a high return on investment.
Analog Vs IP
If you're familiar with a traditional analog CCTV set up, you know that your cameras need to be linked directly to a Digital Video Recorder (DVR) that records, processes, and stores all the data. IP cameras require a Network Video Recorder (NVR) that serves much the same purpose. So, what's the difference? From a technical standpoint, the two recorders differ in where the video footage is actually processed. In an analog set-up, a DVR is responsible for this, while in an IP set-up this is done in-camera and then streamed to the NVR. Because of this, IP cameras can compress and send much higher resolution and picture quality to its recording unit.
High Definition Analog
When video surveillance started over 20 years ago, cameras used an analog signal that was sent through coaxial cable to a DVR that processed, recorded and stored the video footage. The coaxial cable is traditionally paired with an 18/2 power cable that carries power to the camera from an AC or DC power supply. With billions of analog security cameras installed across the world, CCTV manufactures have developed high definition analog cameras and DVRs that can process and record video as high as 4 mega pixels while still using the existing coaxial cable that was ran years ago. There are currently 4 types of analog recording technologies that are present in the mainstream market, standard analog and the 3 high definition technologies include CVI, TVI and AHD.
Traditional HD Analog Set Up:
IP stands for Internet Protocol, and basically refers to a digital video camera that can send and receive data via a computer network, as opposed to sending a feed to a DVR. This is advantageous for a lot of reasons;
1. Picture Quality
IP Cameras have the image processed and compressed within the camera. This decreases the amount of information that is streamed through the cable allowing for higher quality signals to be sent to the NVR. IP Cameras can produce images as high as 30 Mega Pixels. Properly placing one high Mega Pixel IP camera can cover the same area as multiple analog cameras.
Unlike analog cameras, IP cameras do not need to be plugged directly into its recording unit. They send and receive information via a computer network, therefor allowing you to utilize new or existing network switches. On top of that, using one or multiple PoE (Power over Ethernet) switches allows your Cat 5e or Cat 6 cable to run the signal and provide power to your camera, eliminating the need for a separate power supply. The ability to use PoE switches allows installers to run less cable and makes it less labour intensive.
Sample IP Set Up with a Standalone PoE NVR:
Sample IP Set Up Utilizing a PoE Switch:
Which one is right for me?
Many factors need to be considered when deciding between HD analog or an IP solution. Do I have existing analog cameras? Am I looking to expand my existing solution? Is it a new installation?
For existing analog users, using your existing cable is a big factor because the infrastructure is already there. HD analog has ability to utilize that cable and still provide high definition images up to 4 Mega Pixels. But there comes a time when you have to say goodbye to the old and hello to the future of CCTV. Although the initial cost is more, it's important to remember that a single IP camera can take the place of multiple comparable analog cameras due to the increased coverage area, so while a single unit may cost more, you're ultimately buying less cameras.
For new installations, IP solutions are the way to go. Better image quality and the ability of using network switches allow for a more flexible solution. Running less cable and utilizing PoE means it is a less labour intensive installation.
Frame Rate (FPS)
Frame rate refers to the number of individual frames that comprise each second of video you record, also known as FPS (frames per second.) The most common frame rates in CCTV are 30, 20, and 15 frames per second. The more FPS the smoother the video will look and increases the chance you can get the still frame you are looking for. With a higher FPS, you also use more storage and requires more power to process this data. Most standalone DVR and NVR’s have limitations on frame rate based off of the number of mega pixels that the recording is in.
Frames Per Second Comparison:
Hard Drives (HDD)
Hard Disk Drives (HDD) have a series of platters stacked on a central spindle, with a small gap in between them. The platters rotate at up to 10,000 revolutions per minute (rpm) so the read-write heads can access any part of them. Modern day DVR and NVR's use HDD’s to store video footage. When they are full they simply overwrite the oldest data and continue this cycle. The typical HDD size in a recording unit is 1, 2, or 4 terabytes (TB) although HDD’s can be ordered up the 8 TB. One TB is approximately 1,024 gigabytes (GB). Recording units can utilize multiple HDD’s to increase storage size.
When the video is processed by a DVR or IP Camera, the image becomes compressed in order to maximize storage and minimize data being sent back and forth. H.264 or MPEG-4 Part 10, Advanced Video Coding (MPEG-4 AVC) is a block-oriented motion-compensation-based video compression standard. By 2014 it was one of the most commonly used formats for the recording, compression, and distribution of video content.
Today, CCTV manufactures are moving to High Efficiency Video Coding (HEVC), also known as H.265. It is a video compression standard, one of several potential successors to H.264. In comparison to H.264 it offers about double the data compression ratio at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD.
Compression Rate Comparison:
Recording Types (Continuous/Motion)
Most DVR and NVR’s on today’s market have the ability to record strictly on motion to allow for a longer prior of time of recording on the HDD as well as easier searching. Sensitive settings and set motion areas (example - block out a branch swaying in the cameras view) can be set to have more accurate detection.
Continuous recording can be utilized in order to ensure that nothing happened at a certain point in time. The other main use for continuous motion is to monitor gage levels for record keeping.
The most common question when it comes to recording is “how many days of recording will I receive with my DVR or NVR?” Unfortunately, every situation is different and can be very unpredictable. The 4 topics previously mentioned in the DVR/NVR Information section ultimately decides how many days of recording you will receive on your recording unit. Are you maximizing your frame rate with real time recordings or are you running it at half time recording? What is the total amount of storage in your recording unit? How high is the video quality and what compression rate is your recording unit using? How much time during the date is it recording? All these variables determine how many days of recording you will receive with your DVR or NVR.
Approximate Recording Times Using:
TB of Storage on Motion Recording at 30 FPS
Using a simple Internet connection, todays DVR and NVR’s allow you to access its information remotely via computer, tablet or smart phone. The Internet connection is recommended to have a minimum upload speed of 5 mbps and a download speed of 25 mbps. Setting up remote viewing is dependent on the DVR and NVR; some older units require port forwarding and login credentials while most new recorders just require scanning a QR Code and logging in using the units’ user name and password.
Bullet cameras and dome cameras are the most common camera types used for home and business security today. Both are easy to install, manageable, and offer complete control to the user when securing areas of any size. Bullet cameras, as the name suggests, protrude outwards like a gun’s barrel, while dome cameras have the rounded “dome” shape, to all but mark the biggest difference between them. When it comes to functionality, the two camera types possess extreme similarity, but still the small differences can be of great significance considering the specific purpose you are looking to cover.
Dome Camera Benefits
Ideal for mounting on a ceiling or under a soffit Aesthetically more pleasing
Can come in vandal resistant housing
Bullet Camera Benefits
Ideal for mounting on a wall with no overhead coverage Has sun-shield to reduce glare
Generally, has higher IR Distance
Easy to install
Two other popular types of cameras currently on the market are PTZ and covert cameras. PTZ Security Cameras allow you to control the pan, tilt and zoom operations of the camera lens remotely or through a surveillance DVR or NVR. Covert cameras come in all different shapes and sizes. The primary function of a covert camera is record activity and not be noticed. Examples of covert cameras are smoke detectors, motion detectors, alarm clocks and even small pinhole cameras.
The standard measurement of CCTV resolution is mega pixels (MP). The way resolution is measured is the amount of pixel lines horizontally by the amount of pixel lines vertically. Mega Pixel is equivalent to around 1 million pixels. 2 MP is equivalent to 1080p (1920 x 1080) and 8 MP is equivalent to 4K (3840 x 2160). Each technology has a certain MP that they set as their standard. HD analog standard is 2 MP while IP camera standard is 4 MP. The larger the mega pixel the more space they can cover with the same amount of detail. This is important when selecting which cameras, you are going to use for your solution because although one high mega pixel is more expensive, you will ultimately be buying less cameras to cover a certain area and saving on labour.
A security camera lens size determines the field of surveillance view and zoom level that the camera provides. The larger the size of the lens, the narrower and zoomed in the field of view is. The resolution of the camera effects the field of view, the larger the mega pixel the larger the field of view you will receive from that lens size. Most fixed lens cameras come standard with a 2.8mm, 3.6mm or 6mm lens. A 2.8mm lens is designed to provide an approximate 90-degree field of view, a 3.6m lens provides an approximate 72-degree field of view and a 6mm lens provides an approximate 43-degree field of view. If you need precise adjustment to the angle and field of view for your application, a varifocal lens camera is recommended so that you can adjust the lens to the exact view that you need. Varifocal lenses typically come in a 2.8- 12mmlens.
Approximate Camera Angles by Lens Size
Ingress protection (IP) were developed by the IEC (International Electrotechnical Commission) and are most heavily used in Europe, Asia, and North America. Since these are international standards, the testing is often certified by the TUV instead of UL, although both provide stringent testing.
IP65 Enclosure - IP rated as "dust tight" and protected against water projected from a nozzle.
IP66 Enclosure - IP rated as "dust tight" and protected against heavy seas or powerful jets of water.
IP67 Enclosures - IP rated as "dust tight" and protected against immersion.
Wide Dynamic Range (WDR)
When part of an image is extremely dark but another part is so bright you can’t see any details, that’s dynamic range—the difference in lighting. Cameras with wide dynamic range (WDR) have special software that allows them to balance that lighting for one clear image. This makes them ideal for recording areas like store entrances where the contrast between the sunshine outside and the dim lighting inside can be extremely difficult to record.
Cameras have problems with underexposed and overexposed images because they can only accurately record the middle area of light between very dark and very bright. Cameras with WDR technology have advanced sensors that can produce a wider range of lighting, allowing them to record in a higher light depth.
The camera will capture several shots of the scene at different exposure levels. This creates overexposed and underexposed identical images, which the camera will combine. It takes the most balanced parts of both images, creating the recorded image you see. This method requires an extremely fast and light-sensitive sensor, however, and is only available on advanced professional cameras.
Wide Dynamic Range Example:
Infrared illumination is in a frequency range beyond what the human eye is capable of registering as light. Conversely, most video cameras perceive infrared light just as they would any other type of light. IR security cameras have the capability to capture video in low light and no light (0 Lux) areas, because of this they are sometimes referred to as "Night Vision Security Cameras". Infrared cameras have IR LEDs positioned around the outer edges of the camera lens which gives the camera its "Night Vision". Infrared Cameras can capture acceptable video in total darkness and even better quality video in low light. Even a small amount of ambient light helps the overall night vision capability of IR cameras a lot. IR cameras are available in various body styles, such as dome and bullet styles.
IR Sample Image in Moon Light: