Bed Frame Queen Instamatic Provides Your Bed with Perfect Support. The Mantua bed frame queen instamatic has extremely durable features, including a 1.5-inch angle iron construction that cradles your bed's foundation so it does not shift. A double angle support beam runs down the middle to prevent sagging.
Quora User, Digital photography since 2003... Optical zoom is a variable focal length lens, like a 15-85mm or 25-200mm lens. In an APS-C sensor DSLR camera, the standard or prime focal length is 35mm. Any focal length lower than this is called wide angle range. All the focal lengths above 35mm are called tele photo range.
A zoom lens is a mechanical assembly of lens elements for which the focal length can be varied, as opposed to a fixed focal length lens. A true zoom lens, also called a parfocal lens, is one that maintains focus when its focal length changes. A lens that loses focus during zooming is more properly called a varifocal lens. Despite being marketed as zoom lenses, virtually all consumer lenses with variable focal lengths use varifocal design. The convenience of variable focal length comes at the cos