定场镜头是影片一开始，或一场戏的开头，用来明确交代地点的镜头，通常是一种视野宽阔的远景。有时候，定场镜头与涵盖镜头相同，目的在确立场景中所有人物与空间的关系。

An establishing shot in filmmaking and television production sets up, or establishes the context for a scene by showing the relationship between its important figures and objects. It is generally a long- or extreme-long shot at the beginning of a scene indicating where, and sometimes when, the remainder of the scene takes place.