IP Cameras vs. Analog Cameras
There are two primary types of cameras that can be wired into a video surveillance system: IP cameras (internet protocol cameras) and the traditional analog cameras. IP cameras are the more modern iteration of analog cameras, and while the individual cameras tend to be a little more expensive, they offer a number of features that analog cameras do not. Here's a look at the differences between the two types of camera.
IP cameras are far more powerful than analog cameras, usually shooting footage of between 1 megapixel and 5 megapixels. That makes for incredibly clear image quality, especially compared to the more grainy analog footage, which runs around one-half of a megapixel. IP cameras generally have a larger field of vision than analog cameras.
IP cameras also have additional features that analog cameras don't offer, such as video analytics, which allow for mobile notifications and automatic recording if there is movement within the camera's field of vision. This is particularly useful for times when your business is closed and you want to know if someone is moving around inside the premises. You can configure the system to flag events like this and send notifications directly to your smartphone, along with recorded footage of the event. Some systems also offer a direct, one-touch connection to local law enforcement.
Network Video Recorders
In addition, IP cameras are compatible with network video recorders (NVRs), which offer several other benefits over the older digital video recorders (DVRs) that this guide will cover. In short, NVR records higher-quality video and allows for systems to be scaled up much more easily than can be done with DVR. For more information on video recorders, see the section below.
PoE Switches (Power over Ethernet)
IP cameras can also be connected to what is known as a "power over Ethernet" switch, which both sends data from the camera and provides power to it. Analog cameras, on the other hand, require a switch to run the signal from the camera as well as a separate power source, meaning a more complex setup and more wires. PoE switches are also generally regarded as a more secure way to transmit data.
Comparable System Cost
While IP cameras are generally more expensive than their analog counterparts, the total cost of a full IP system tends to be slightly lower than that of a comparable analog system. Since IP cameras have a wider field of vision, as well, an IP system can often work with fewer less cameras than an analog system.
Digital Video Recorders vs. Network Video Recorders
All of the cameras in a given system require a central video recorder in order to transmit and archive the footage they are capturing. DVRs evolved from the older VCR models, while NVRs represent the next step in the evolution of video recording technology. Here's a side-by-side look at how DVRs and NVRs compare.
Resolution of recordings
DVRs generally offers traditional video quality used in closed-circuit television systems.
NVRs can record in 1080p, which is high-definition. 1080p equates to a resolution of 1920 x 1080. This results in a much clearer image.
Connecting analog cameras with a DVR system is done by way of directly plugging a BNC cable from the DVR into the camera. To connect more cameras to the DVR system, you need additional cables. DVR systems are difficult to scale up because once every BNC connection is occupied by a camera, you need to purchase an entirely new DVR before adding another camera to the system. DVRs also require that the connected cameras be in close proximity to the recorder; otherwise, the video quality begins to degrade.
The NVR eliminates these problems, because it is instead connected directly to a network. IP cameras that are connected to the same network, usually by way of a PoE switch, are then able to transmit footage to the NVR. Systems based around an NVR are much easier to scale up than DVR systems, simply because they can accept a new camera once it is added to the network. In the worst case, all that would be required is an additional PoE switch. Some IP cameras are also wireless and can transmit footage to the NVR over Wi-Fi. There are no proximity limitations so long as a camera is connected to the same network as the NVR. The largest downside to an NVR system, however, is that not every IP camera will work with every NVR. So you'll need to know whether your cameras will be compatible with a given video recorder before buying.
Hybrid Video Recorders
Hybrid video recorders (HVR) are video surveillance systems that run both IP cameras and analog cameras.
What to Look for When Choosing a System
Resolution: This is one of the most important considerations when selecting a camera. For a sharp image, you'll want a camera that can shoot at least in 720p high definition, which means an IP camera. If you want to guarantee that your camera will have a clear, identifiable image, you don't want to cut corners here.
Frame rate: This is another key aspect of a camera — the higher the frame rate, the smoother the video. Video is simply a series of still images stitched together to create a motion picture. The lower the frame rate, the less frequently a still is taken; this results in choppier footage. You'll want to consider the frame rate of the camera you purchase before deciding. For reference, "real time" is typically measured as 30 frames per second.
Models: There are a number of different types of security cameras out there. Some of the more common ones are bullet cameras, which are the rectangular boxes you might see protruding from a wall; dome cameras, which are often attached to a ceiling and housed in a tinted cover; and pan-tilt-zoom (PTZ) cameras, which offer remote-control capabilities to adjust the field of vision. Depending on your particular security needs, you'll want to consider which types of cameras to use in outfitting your system.
Indoor/outdoor: Some security cameras are made specifically for the indoors and won't stand up to Mother Nature quite as well as their outdoor counterparts. If you plan to use cameras outside, make sure you purchase models that are weatherproof. Otherwise, water or dirt might interfere with the quality of your video feeds or, worse yet, break your camera. Security cameras might be minimally resistant to weather or completely weatherproof. Be sure to understand what level of protection from natural conditions your security camera offers.
Lighting: Many security cameras are able to shoot in what is known as "low-light infrared," enabling them to capture clear footage in dark conditions. These cameras rely on infrared LED lights, which cover the darkened area in infrared light. Unlike humans, the camera is able to see this infrared light, so when those wavelengths reflect back, it's as if the camera is shooting footage in an illuminated room. The more IR LEDs that a camera has, the better it is able to see at night. If capturing footage in the dark is a priority, make sure your camera has plenty of IR LEDs.
Audio: Whether audio recording is an option depends on the particular camera and the manufacturer. Some cameras don't pick up audio at all, while others do. Some even enable two-way audio, so a person watching the camera on the other end can communicate with a subject in the camera's field of vision.
Storage capacity: For video recorders, the first question you have to ask yourself is how much storage you will need. The answer hinges on a couple of factors: the number of cameras in your system, each camera's resolution, the amount of archived footage you intend to store and how long you plan to keep recorded footage. If there are many cameras shooting in a higher resolution, the footage is going to eat up storage space quickly. You can set a video recorder to "overwrite" the oldest footage once you reach the system's capacity, but if you're not careful, the system might overwrite archived footage that you still need.
If you're running a large system that has high-quality cameras, you'll want to scale up your video recorder's storage capacity. There are a number of tools online that can help you calculate how much storage space you'll need based on the details of your system.
For example, a four-camera system that runs 24 hours a day using IP cameras, each with a 2-megapixel resolution and a frame rate of 5 fps, with video compressed into MJPEG files on a NVR, would require 2.79 terabytes of storage space for footage, according to the Supercircuits calculator.
That's quite a bit of data for a moderate-size system, so it's important to plan accordingly and know what kind of capacity you'll really need. It's also wise to maintain a bit of a cushion beyond that calculated number, so you can store any particularly interesting footage you might need to refer back to.
Cloud storage: Recorded video can be stored on the cloud in addition to on your video recorder. There are a few distinct advantages to doing this, including having remote access to your videos and superior storage volume. It's important to ensure that uploading large video files is done in a manner that won't eat up all the available bandwidth and slow down your network. This can be done by either scheduling video uploads to the cloud or uploading them after peak business hours. In addition, be aware that many cloud services charge a subscription fee to use their offerings, especially to store video files in perpetuity. Make sure the company takes the appropriate cybersecurity measures to protect your data. On the plus side, storing videos in the cloud means that even if your hardware is damaged, stolen or tampered with, you'll still have access to your video archives.
Camera compatibility: Not every video recorder can work with every camera. Of course, DVRs require analog cameras, while NVRs use IP cameras, but the compatibility question extends well beyond that distinction. Some NVR systems, for example, are compatible with the IP cameras only from certain manufacturers and not others. When buying a video recorder, you must first make sure that the device will work with the cameras you've purchased. If you're working with a surveillance system integrator to configure your system, the cameras should be able to provide you with the necessary information.
Compression: Compression is used to eliminate unnecessary data from the footage transmitted to your video recorder, thereby saving space. Two of the more common compression techniques used for high-definition video are MJPEG and H.264. You can also use MPEG4, but the quality tends to be lower than that of MPEG4's aforementioned counterparts. Compression methods are relatively complex and vary in their applications depending on your needs and hardware.
Power-over-Ethernet switches apply only to NVR systems, but they cut out other components that would be necessary for a DVR system, like additional power sources and the BNC cables used to connect cameras to the DVR. Instead, when you connect a PoE switch to your network, you've got a power source and a means of transmitting data to your NVR all in one package. The biggest consideration when choosing which type of PoE switch to buy is the number of cameras that will be on your system. The next consideration is how likely you are to scale up in the future.