Bullet vs. dome vs. PTZ: Which one to choose?
Source: William Pao, a&s International
have different types. The primary ones are bullet, dome and PTZ which can be confusing to users. Understanding their benefits and limitations, therefore, is important in helping the user decide which one to choose.
Needless to say, security cameras are more and more moving towards IP, which carries various benefits, including higher resolution
, integration with other IP systems and ease of installation using PoE where both data and power are delivered. Before purchasing an IP camera, though, several things need to be considered, including which type – bullet, dome or PTZ – to get.
Bullet cameras are shaped exactly like a bullet. They have a fixed or variable focal length and point at one direction at a time so they can be useful in targeting a specific area of the property. They are typically indiscreet in the way they are installed, and as a result they serve as an effective visual deterrent for criminals. Additional benefits include easier installation and cheaper prices, compared to domes and PTZs. However they may not be as vandal-proof as the other types, so placing them at less reachable places may be ideal.
are so named due to their dome-shaped body. Capable of easily blending into a facility’s internal environment, they are usually placed inside on a ceiling, although they can also be attached directly to a wall. Unlike bullet cameras, they are more low-profile and offer a more discreet way of keeping premises under surveillance. Like bullet cameras, dome cameras’ field of view cannot be changed; however the direction the camera is pointing to is typically not immediately noticeable, and this can be an advantage. Dome cameras are more vandal-resistant as well.
are dome-shaped and allow the user to remotely control the camera so it can pan, tilt and zoom in/out, providing an effective means for surveillance.
According to a recent blogpost
by Kintronics, a PTZ camera’s lens zoom and resolution are important factors to consider. “The lens is measured in focal length (mm or angle). The capability of the zoom is defined by the ratio of the smallest focal length (narrow) to largest (wide) mm settings. For example, there are 12X zoom lenses that can be adjusted between 5.2 mm to 62.4 mm,” the post said. “The resolution establishes the field of view. The more resolution, the more detail we can see in the field of view. For example, if we use a 2-Megapixel camera, we can read a license plate in a field of view that’s about 9.7 meters wide. If we use an 8-Megapixel (4K) camera, we will be able to read the license plate in a field of view that’s 64 meters wide.”
Further, the low-light sensitivity of the PTZ is crucial if the user needs to see things when it’s dark. “The better quality PTZ cameras have improved low light sensitivity, with some being able to see in color as low as 0.02 lux or at 0.002 lux in BW (gray-scale),” the post said.
In the end, selecting the right camera type requires an understanding of the camera type – what are its benefits and limitations – as well as the user’s own objectives and requirements – Where do I want to install the camera, how much field of view do I need, how visible do I want the camera to be, and how well do I need to see at night. Only by figuring these out can the user get the camera that best fits their needs.