A bird's-eye view is an elevated view of an object or location from a very steep viewing angle, creating a perspective as if the observer were a bird in flight looking downwards. Bird's-eye views can be an aerial photograph, but also a drawing, and are often used in the making of blueprints, floor plans and maps. Before crewed flight was common, the term "bird's eye" was used to distinguish views drawn from direct observation at high vantage locations (e.g. a mountain or tower), from those constructed from an imagined bird's perspectives. Bird's eye views as a genre have existed since classical times. They were significantly popular in the mid-to-late 19th century in the United States and Europe as photographic prints. The terms aerial view and aerial viewpoint are also sometimes used synonymous with bird's-eye view. The term aerial view can refer to any view from a great height, even at a wide angle, as for example when looking sideways from an airplane window or from a mountain top. Overhead view is fairly synonymous with bird's-eye view but tends to imply a vantage point of a lesser height than the latter term. For example, in computer and video games, an "overhead view" of a character or situation often places the vantage point only a few feet (a meter or two) above human height. See top-down perspective. Recent technological and networking developments have made s more accessible. Microsoft Bing Maps offers direct overhead satellite photos of the entire planet but also offers a feature named Bird's eye view in some locations. The Bird's Eye photos are angled at 40 degrees rather than being straight down. Satellite imaging programs and photos have been described as offering a viewer the opportunity to "fly over" and observe the world from this specific angle. In filmmaking and video production, a bird's-eye shot refers to a shot looking directly down on the subject. The perspective is very foreshortened, making the subject appear short and squat.