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.
Report Abuse. 100-300mm refers to the focal length of the lens, in this case it's a varibale focal length lens or, more commonly, a zoom lens. Focal length is the distance from the optical center of the lens to the focal point (or the point of focus). On a camera the focal point is the film plane or the digital sensor.