What are the three major optical phenomena in industrial lenses?

The three major optical phenomena in industrial lenses are the focal length, angle of view and aperture of the lens.

1. Focal length: The lens is composed of a series of multiple concave lenses and convex lenses with different materials and shapes. A single lens is called a lens unit, and multiple lens units form a whole, which is a photography lens. The longer the focal length, the larger the image formed. The shorter the focal length, the smaller the image formed.

2. Viewing angle: refers to the range of images that can be seen and recorded by the lens. There is a rectangular frame in front of the image sensor in the camera, and the size of the inner edge of the frame determines the image field range. The angle between the lens center and the image field diameter is the image angle, and the viewing angle is equal to the image angle. The focal length of a lens is inversely proportional to the angle of view. The longer the focal length of a lens, the smaller its angle of view.

3. Aperture: The effective aperture of a lens, referred to as aperture, indicates the lens's ability to collect light and is the ratio of the lens's maximum light entrance diameter to its focal length. In layman's terms, it is the maximum aperture of the lens. The aperture size of the lens is expressed by the aperture coefficient F. The value of F is equal to the ratio of the lens focal length to the maximum aperture diameter. Caliber notation: For example, a lens with a diameter of 2.8 can be written as F2.8 or 1:2.8. The smaller the F value, the larger the diameter, and vice versa.