The day after Christmas was also the traditional day on which the aristocracy distributed presents (boxes) to servants and employees  a sort of institutionalized Christmas-bonus party. The servants returned home, opened their boxes and had a second Christmas on what became known as Boxing Day.
300 mm. For a 35 mm camera with a diagonal of 43 mm, the most commonly used normal lens is 50 mm, but focal lengths between about 40 and 58 mm are also considered normal. The 50 mm focal length was chosen by Oskar Barnack, the creator of the Leica camera.
On a full-frame camera, a normal lens is considered to have a focal length of 50mm. This was set by the creator of the Leica camera system, Oskar Barnack, pretty much arbitrarily. In reality, any lens with a focal length of between about 40mm and 58mm will look roughly like how things appear to your eyes. On a crop sensor camera, a normal lens is usually taken to be about 35mm, although any lens with a focal length that falls between about 28mm and 36mm will work. Comparing Lenses Here are three photos of the same scene, though Iâve moved the camera position to keep the size of the subject approximately the same.