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.
In photography and cinematography, a normal lens is a lens that reproduces a field of view that appears natural to a human observer. However, to find a photographic lens equivalent to the human eye, which has an effective focal length of approximately 17mm, is problematic due to the nature of human binocular vision, being mediated and processed by the cortex, and because of the structure of the human eye which has a concave retina, rather than a flat sensor, with variable sensitivity and resol