The most important and basic characteristic of a lens is the value of its focal length. Moreover, the lens itself is considered the most important part of any camera. The values that measure the focal length can be different.
What is focal length
The lens is a complex system consisting of several optical lenses. At the moment of pressing the camera shutter, the image enters the lens, refracts there and converges to one point, which is at a certain distance from the rear of the lens. This point itself is called the focal point, or focal point, and the distance separating the focal point from the lens system is called the focal length. It is measured in millimeters.
The smaller the value or number of the focal length, the larger the shooting area fits into the frame, and the larger it is, the closer the lens shows distant objects. Small focal lengths are used for shooting landscapes, architectural ensembles, large groups of people. Long focal lengths are good for animals and birds, for sports and whenever you need to get a close-up shot. Approximately corresponds to the viewing angle of the human eye, which is 46 degrees, focal length 50 mm.
Lenses with a focal length of less than 35mm are called wide-angle lenses. Nature and architecture can be easily captured with their help, but the wider the angle and the shorter the focal length, the greater the optical distortion will be observed in the pictures. When shooting columns or pillars with a lens with a focal length of 24 mm, the columns from the edges will tilt inward, rounded. The fish-eye effect is achieved with lenses smaller than 20mm.
Lenses with long focal lengths are called telephoto lenses, and lenses with very long focal lengths are called telephoto lenses. In addition, there are lenses whose focal length is fixed - the so-called "fixes" and lenses with variable focal lengths, called "zooms". Fixed focal length lenses are a more budget option and allow you to get better quality images than a zoom lens at the same focal length.
What is the optimal focal length
Wide-angle and ultra-wide-angle lenses with focal lengths less than 20 mm and up to 35 mm are suitable for shooting architecture and landscapes. To work with portraits and genre photography, normal and telephoto lenses with a focal length of 35 to 135 mm are suitable. For sports photography and for work in nature, telephoto lenses are suitable, the focal length of which is from 135 to 300 mm or more. With zoom lenses, you can shoot from and to the limits of the zoom, which may differ from model to model.
