An aperture of 2.8 might make the trees and shrubbery look silky smooth, but it might make Uncle Bob at the end of the line look fuzzy.

• 2.；8的光圈值会使背景的树啊灌木啊如牛奶般柔滑，不过同时也可能把站在最边上的大叔拍模糊了。