Photographing insects requires a large aperture and high speed, but since this severely reduces the depth of field, it was almost impossible to take a picture of a single insect without some part of it being out of focus.
但是光圈一放大，景深就淺，拍攝出來的照片便會模糊。如果把光圈縮小，速度減慢，又不能用三角架（機動性不夠）。