远近镜或称分焦镜 ,它实际上只有半个近摄镜头 ,另一半是空的。用远近镜可以使在一幅画面上的远景和近景的焦点都清楚 ,以利进一步加大景深。例如 ,近处是餐桌 ,远处是建筑物 ,不使用远近镜 ,就不可能有足够的景深使近景和远景都清楚 ,如果把焦点对在建筑物上 ,近景就不清晰 ; Near and far mirror or focus lens, it is actually only half a close-up lens, the other half is empty. With the near and far mirrors can make in a picture of the distant and close focus of the focus clearly, in order to further increase the depth of field. For example, in the immediate vicinity of a dining table and in the distance buildings, without the use of near and far mirrors, it is impossible to have sufficient depth of field to make both close-ups and distant views clear. If the focus is on a building,