A lens is an optical device that transmits and refracts light, and the final effect depends entirely on the precision of the lens design and the optical quality inside the lens.
      The type of lens

•       Fixed focus lens: Fixed focus lens is a fixed focal length lens, which means that the lens has only one length called distance, is fixed. It focuses precisely on a certain focal length, rather than several focal length segments, so it typically produces clearer images than a zoom lens. Because fixed-focus lenses require fewer optical parts and a larger aperture, the aperture can be opened in low-light environments for a shallower depth-of-field effect, sometimes reaching f/1.2. The fixed-focus lens cannot zoom, which means that the photographer needs to move the position close to live away from the subject.

•      Zoom Lens: Zoom lens allows the cameraman to change the focal length of the lens, bringing the subject closer or farther away without the photographer moving the position. The photographer is more convenient to use the zoom lens, which allows him to approach the subject and compress the perspective when needed. Zoom lenses are now as sharp as fixed-focus lenses and often have the best "aperture" to indicate the sharpest lens at a certain focal length and aperture. The zoom lens has a certain number of lenses inside, which is much heavier than a fixed-focus lens, and even the most expensive lens has a maximum aperture of about f/2.8.

• Telephoto lenses: Lenses with a longer focal length, which have a shorter focal length than physical focal lengths, such as lenses with a focal length of 300mm, but a shorter physical focal length than 300mm, extend the path of light and produce lenses with longer focal lengths and shorter lenses. The telephoto lens has a fixed-focus lens as well as a zoom lens.

     Wide-angle lens: Wide-angle lenses have a shorter focal length than standard 50mm lenses, usually 35m or less. We know that telephoto lenses compress the perspective of the image and take photos at shallower depths of field, while wide-angle lenses increase the sense of space and create a wider depth of field. Wide-angle lenses are widely used in the fields of architectural photography and landscape photography. Its perspective is generally deformed, which causes parallel lines to converge, resulting in barrel distortion.

• Pitch and swing lenses: Asymmetrical pitch and swing operations can be performed to ensure that the subject plane, lens plane, and image sensitivity plane intersect at a virtual point. Its lenses are mainly used in studio products, indoor and architectural photography.
        Macro lens: For macro photography, it is also suitable for closer photography. You'll often see beautiful photos of macro plants and insects, and you can even see details such as tiny hair, all taken with macros.
        Product photography when selecting lenses, mainly consider the subject of shooting, the purpose of photography is to use photos to record the best and most attractive side of the product. One rule is that the photos are clear, because the potential market needs to be clear about what the audience is selling. In general, take the best light and ensure that the photo faithfully restores the subject.