As is usually the case, in the absence of multi-diffraction, the lower limit of the off-axis, angle of the mirror defined by themethod is better than the value given by Cary principle.

• 在许多场合,采用这个方法所确定的不存在多重衍射时反射镜离轴角的下限,将优于Cary原理所给出的数值。