The one-half wavelength out of phase caused by the specimen itself enables this light to cause destructive interference with the direct light when both arrive at the intermediate image plane at the diaphragm of the eyepiece.

• 这种由标本产生的半个波长的相位差的光线与直射光同时到达位于目镜光栏的中间像面时会产生相消的干涉。