首先要说明的是该处所说的容许弥散圆是指负片，的，因为在日常生活中，容许弥散圆还可指照片上的。 一个物体被镜头成像，在理想状况下是点与点一一对应的。但在实际上，由于光波的性质、如像差的影响，物体上的点经镜头成像后可能就不是一点，而是成了一圆点，由于人眼的分辨 The first thing to note is that the tolerance circle referred to here means negative, because in everyday life, the circle of permissiveness may also refer to the photograph. An object is imaged by the lens, ideally point-to-point correspondence. However, in fact, due to the nature of the light wave, such as aberration, the point on the object after the lens imaging may not be a little bit, but into a dot, due to the resolution of the human eye