Fast lenses are camera lenses with a large maximum aperture, typically f/2.8 or wider. This allows more light to enter the lens, making it easier to capture images in low-light conditions. Fast lenses are favored by photographers for their ability to create a shallow depth of field, which helps isolate subjects from the background, resulting in a pleasing bokeh effect. These lenses are often used in various photography styles, including portrait, street, and event photography. Popular fast lenses include those made by brands like Canon, Nikon, and Sony. Their versatility and performance make them essential tools for both amateur and professional photographers.