What is a Network Camera, and How Does It Work?

An IP camera (Internet Protocol camera), also known as a network camera or IP security camera, is a type of surveillance camera that receives video data over an IP network and transmits video segments. It is commonly used as a remote monitoring and management tool in various industries and environments to safeguard properties or monitor homes, businesses, or public safety. By connecting to the network, including network video recorders (NVRs) and monitors, IP cameras allow you to monitor specific areas from any remote location, bringing convenience to our daily lives.

How Do IP Cameras Work?

The operation of IP cameras is similar to digital cameras in capturing high-quality images. What sets them apart is that IP cameras can compress these files and automatically transmit them to Network Video Recorders (NVRs) over the network.

Typically, IP cameras are connected to the network via Ethernet cables with broadband modems or routers or wirelessly through Wi-Fi routers.

In buildings already equipped with a network, connecting IP surveillance cameras and other devices to your network system is as simple as connecting a laptop or smartphone to your Wi-Fi network.

Once everything is connected, the camera can start capturing video clips and transmitting them to the network video recorder.

Three Common Types of Network Cameras

Various video surveillance solutions employ different types of security cameras. Among these, three types are most commonly used:

Dome Cameras, Bullet Cameras, Turret Cameras

Installation Position

Type Dome Cameras: Installed on ceilings

Bullet Cameras: Installed on walls/ceilings

Turret Cameras: Installed on ceilings

Advantages

Dome Cameras: Wide field of view; discreet appearance; less invasive compared to bullet and turret cameras

Bullet Cameras: Long-range view; easy to install or reposition; less IR reflection; more conspicuous, deterring criminals

Turret Cameras: Long-range view; easy to install or reposition; less IR reflection; more conspicuous, deterring criminals

Disadvantages

Dome Cameras: Difficult to reposition after installation; prone to IR reflection; easily collects dust or fingerprints

Bullet Cameras: More susceptible to damage than dome and turret cameras; limited monitoring angle

Turret Cameras: Vandals can change direction

Applications

Dome Cameras: Schools, offices, homes, or small shops

Bullet Cameras: Schools, stores, industrial settings, traffic lights, and high-crime areas

Turret Cameras: Schools, offices, homes, or small shops

Four Key Specifications of Network Cameras

When looking for a security camera, you should not only determine its type but also pay attention to specifications that can make a significant difference. There are four fundamental specifications:

1. Resolution: The total pixel count constituting the image, commonly measured in width and height. Common resolutions include 720p, 1080p, 5MP, 4K, and 8MP. Higher resolution usually means more pixels per inch (PPI), resulting in high-quality, clear images.

2. Field of View: The camera's lens allows you to compose the area you want to focus on. Different lens systems have different fields of view, determining the width of the area you can see. A wider field of view allows the camera to cover a larger area. Different lens angles are needed for large parking lots and small rooms.

3. Focal Length: The focal length of the lens (measured in "mm") determines the field of view and the distance the camera can see. There are two types of lenses: fixed lenses and zoom lenses. The most common fixed focal length is 3.6mm, resulting in a 90° field of view and a distance of 20 feet. There is also an 8mm lens with a 40° field of view and a recognition distance of 40 feet.

For zoom lenses, the most common is the 2.8-12mm lens. At 2.8mm, you get approximately a 100° field of view with a recognition distance of about 10 feet. At 12mm, you achieve about a 30° field of view and recognition at about 50 feet. The wider the focal length, the farther the focus distance, and the narrower the field of view.

4. Low Light Sensitivity: Low light sensitivity, usually measured in lux (lx), refers to the camera's ability to provide high-quality images by rendering details and reducing noise in the output image even in low light conditions. Factors affecting the camera's low light performance are few, including pixel size, signal-to-noise ratio, lens aperture, etc. Lower lux values allow the camera to present high-quality images in darker areas. For example, cameras with 100-1,000lx are used for recording under workspace lighting, while cameras with 0.0001lx are typically used for moonless or overcast nights.