Classification and principle of the zoom lens

The zoom lens is a lens that can continuously change the focal length. Relative to fixed focal length, it is a lens that can continuously change the focal length. In addition to the fixed lens group, there are also movable lens groups. The zoom lens consists of three parts: wide, standard, and long. One lens can not only replace three kinds of lenses but also continuously change the scene of the picture by continuously changing the focal length to form the effect of pushing and pulling the lens. The focal length of the zoom lens is generally between 28 and 200 mm.

Here is the content list:

●Classification of the zoom lens

●Zoom lens zoom principle

Classification of the zoom lens

According to the overall dimensions, the camera lens is divided into a box lens and a portable lens. Theoretically, the lens of a box lens is larger and its optical characteristics are stronger than that of a portable lens. The focus change and focus of the box-type lens can only be carried out by the zoom and focus servo handle, while the zoom and focus of the portable lens can be selected by the switch on the lens.

According to the zoom range, the camera lens can be divided into the wide-angle lens, standard lens, and telephoto lens. Focal length is a basic feature of the lens, which can determine the magnification of the image and the size of the horizontal field of view taken by the lens. The focal length is determined by measuring the distance from the optical center of the lens to the point where the light converges behind the lens to produce a clear image. The shorter the focal length, the wider the horizontal field of view, and the smaller the image. The horizontal field of view narrows as the focal length increases, and the subject increases.

Zoom lens zoom principle

Optical zoom is to change the position of the focus, the length of the focal length of the lens, and the size of the angle of view of the lens by moving the lens inside the lens, so as to realize the enlargement and reduction of the image. In the image above, the longer right angle of the red triangle is the focal length of the camera. When you change the position of the focus, the focal length will also change. For example, if the focus is moved in the opposite direction of the imaging plane, the focal length will be longer and the angle of view in the image will be smaller. In this way, the scene within the visual angle range will become larger on the imaging surface.

Nanjing Rising Opto-Electronic Co., Ltd is mainly engaged in infrared lenses, laser lenses, etc., and is recognized as the leader in high-performance infrared optical equipment in China. Our company has professional production equipment and an authoritative technical team. Our customers are all over the world and have been widely recognized by customers during the cooperation. Before the product leaves the factory, we will carry out strict quality tests to ensure the quality of the product. If you want to know more information about zoom lenses, welcome to consult us. Our website is www.risingoptic.com.