A standard lens, often referred to as a normal lens, typically has a focal length of around 50mm for full-frame cameras. This focal length closely mimics the perspective of the human eye, making it ideal for capturing natural-looking images. Standard lenses are versatile and can be used for various photography styles, including portraits, landscapes, and street photography. These lenses usually have a wide maximum aperture, allowing for good low-light performance and the ability to create a shallow depth of field. Standard lenses are popular among both amateur and professional photographers due to their balance of size, weight, and image quality.