NVR

NVR or Network Video Recorders record video data that is created or “encoded” by network security cameras, also known as IP cameras for short. There are two major types of IP cameras that are used with an NVR:

1. PoE Cameras are wired IP cameras that use Ethernet or networking cable to provide power and data.

2. Wireless IP cameras, also called WiFi security cameras, usually require a power source and connect wirelessly to a WiFi network. 

Power over Ethernet cameras offer the most convenience because they receive a power and data connection over a single cable. PoE eliminates the need for a power source nearby, and does not rely on intermittent wireless connections. Another big convenience is the plug and play feature that is prevalent in IP camera systems when purchasing compatible equipment. Plug and play compatibility makes installation and configuration a breeze. This is because plug and play systems will automatically configure IP cameras to connect and record to an NVR system. 

Wireless IP Cameras offer some convenience but are not reliable for professional surveillance systems. Wireless cameras work by having a power source nearby and connect using WiFi radios to a wireless router or network. While the prospect of using wireless or WiFi security cameras sounds promising, it is riddled with limitations and need for maintenance.

Wireless security cameras are great when their limitations of use are taken into account. A 4 camera wireless security camera system is certainly possible for a home that is no larger than 2400 sq ft with a few caveats:

* The cameras need to be connected to a 110V AC power outlet nearby to provide continuous power

* The WiFi signal path from the router or WiFi access point cannot be more than 250ft (clear line of sight)

* The WiFi signal reaching the camera should be 90% signal strength. You can check WiFi strength at a location by using a smartphone as explain our guide on How to use Wireless Security Cameras with a WiFi Router

Wireless are also great for scenarios where it is impossible or too costly to run a wire. For example, if there is a paved parking lot that requires security cameras, it may be the easiest to deploy wired IP cameras paired with WiFi Access Points to make them wireless. While costly, the results are impressive. We suggest reading our guide on how to make a wired camera connect wirelessly to learn more.

IP cameras are smart cameras that contain advanced hardware for capturing and encoding video. This means that IP cameras can also be used as standalone cameras, some support internal microSD cards for local recording. The advanced hardware also allows for newer features like video analytics, noise reduction, and other image processing tweaks.

Thermal Cameras

Thermal imaging can be used in lots of different scenarios. Energy and utility companies can use it to see where houses might be losing heat through window cracks and doors. Police helicopters use it to locate and track suspects at night. Weather trackers can use it to find hurricanes and storms. It can also be used in the medical field to track fevers and diagnose different diseases and disorders. Home security doorbells, such as Ring Doorbells, can use it too.  

Thermal imaging is a type of camera imaging that allows you to see the heat of an object as it radiates off the object. Thermal cameras can be used to record the temperature of various objects in the frame. It assigns each temperature a certain shade of a color. This lets you see how much heat it has compared to the objects around it.

Colder temperatures normally show a shade of purple, blue, or green. In addition, warmer temperatures show shades of red, yellow, or orange. Because of this, the person or object with hotter temperatures will stand out because of the differences in colors. Some thermal cameras may use grayscale instead. Most police helicopters use grayscale, so the suspects stand out more.

Thermal imaging cameras detect the temperature by capturing and recognizing the different levels of infrared light. You can’t see this light with the naked eye, but you can feel it as heat if the intensity is enough.

Every object emits a different type of infrared radiation, and it is how heat transfers. If you hold your hand over something hot, like a fire, it is emitting a lot of infrared radiation, and the heat transfers to your hand. For example, only half of the sun’s energy is emitted as visible light; the rest is infrared and ultraviolet light. The more head an object radiates, the more infrared radiation it emits. Thermal cameras see this radiation and convert it to an image that we can see through colors with our eyes. It is just like how night vision cameras can capture invisible infrared light and make it into a picture we can see.

Inside a thermal camera, there are some tiny measuring devices. These devices capture infrared radiation, called microbolometers. From here, the microbolometer measures the temperature and assigns a pixel that is an appropriate color. Most thermal cameras have a low resolution compared to modern televisions and other displays because of this. A good resolution for a thermal camera is 640×480.

Technically thermal imaging can be called a different type of night vision. For example, in police helicopters, thermal night vision is an advantage. This is because it can easily differentiate between a person and the rest of the environment. This makes it easier to sport suspects in the dark and also in broad daylight when someone might have blended in with their surrounding environment. However, most thermal imaging cameras rely on the wavelengths of infrared. Your typical night vision security camera usually captures shorter wavelengths of infrared, and it cheaper to manufacture. Thermal cameras have the ability to capture longer wavelengths of infrared, which allows it to detect heat.