— lenses in which you can change the focal length in a certain range. This feature is colloquially referred to as "zoom"; it allows you to zoom in and out of the image in the frame by changing the lens settings. Accordingly, this optics is more versatile than fixed lenses: the photographer gets the opportunity, without moving, to change the viewing angle and the size of the scene that enters the frame. On the other hand, variable focal length complicates the design of the lens, makes it more cumbersome, heavy and expensive, and also negatively affects aperture ratio — including because the aperture ratio decreases with increasing focal length, and the elimination of this phenomenon further increases the price. However, in many situations (filming mass events, reporting, etc.) all these shortcomings are compensated by the versatility described above.
