So if you think about the points of light that show up radially from the vision of the camera, which is the thing that matters: how many points of light can I get in a given volume?
所以如果你想象一下关键的问题， 在摄像机视线范围内 能看到多少光点？ 而同样的数量的光点中 我又能看到有多少？