Camera zoom explained in one line: optical zoom moves glass, digital zoom crops pixels. Only one of them keeps image quality. This short guide covers the difference and how security camera zoom is specified on a datasheet.
Camera Zoom Explained: Optical vs Digital Zoom
What is zoom: to understand the basics
Zoom means that the optical device (such as the camera lens) has the function of adjusting the focal length at will, so as to realize the amplification or reduction of the shooting subject.
Traditional camera lenses usually have a fixed focal length, which needs to be replaced with different focal lengths to achieve different perspectives. The zoom lens, on the other hand, integrates multiple optical components of different focal lengths and adjusts them mechanically or electronically to change the focal length in actual use.
Zoom provides greater flexibility and convenience, allowing photographers to adjust the size and range of the subject as needed. By pulling in or away the lens, objects far or near can be captured and change the relationship between the background and the subject.
During the zoom process, the image distortion, color difference and other problems may occur due to the change in the relative position between the optical elements. As a result, high-quality zoom lenses typically employ complex designs and quality materials to minimize these problems and provide as clear and accurate images as possible.
In short, zoom means that the optical device has the function of adjustable focal length, so that the photographer can change the size and range of the shooting subject at will. It provides greater flexibility and convenience, allowing photographers to adjust the shooting perspective without changing the lens.
Optical Zoom vs Digital Zoom on a Security Camera
See optical zoom in practice on our 20X optical zoom PTZ camera and 5MP movable PTZ camera.
- CCTV lens and field of view calculator — the coverage width and pixel density a given lens delivers at your mounting distance
- camera coverage and count planner — how many cameras an area needs at the quality level the footage has to meet
