1·Since eyepieces are interchangeable, a telescope can be used at a variety of powers for different applications.
由于目镜是可更换的，望远镜根据需要可以有不同的放大率。
2·A good eyepiece will render a sharp image in the central parts of the field of view, but toward the edge not even the best and most expensive eyepieces can produce a perfect image.
好的目镜在视场中央成像锐利，但在目镜的边缘即使最好和最昂贵的目镜成像也不行。