Photography is at a distance of 30 meters. If you shoot a sparrow, the picture can count the hair. What kind of fixed-focus lens do you need at least?

Canon 70-300, I hesitated between loving Guo Xuwei and this one before, and finally chose this one, which feels very suitable for me. First, the length, size and weight of the lens are moderate and easy to carry. Second, the focus is fast and the imaging is very sharp. Not losing the third place in Guo Xuwei, the red circle and the white cannon can satisfy the psychology of 13. Nice bird head.