一幅照片中景物影像的清晰范围由景深长短来决定,而景深长短则取决于三种因素。一是光圈的大小:光圈愈大,景深愈短;光圈愈小,景深愈长。二是摄距的远近:被摄物离相机镜实跄离愈近.景深 The clear range of the scene image in a photo is determined by the depth of field, and the depth of field is determined by three factors. First, the size of the aperture: the larger the aperture, the shorter the depth of field; the smaller the aperture, the longer the depth of field. Second, the distance from the camera: the subject is closer to the real camera lens