“It must be emphasized that it was necessary  in the present study to overexpose the diffraction patterns to observe the faint, diffuse satellites. This is probably because of the broad spectrum of composition wavelengths present in the alloy crystals.”

以上是原文中的一段话，意思是由于合金晶体中成分波长的范围较宽，所以需要过度曝光衍射花样来观察一些微弱的卫星斑点。我想请问一下在透射电镜操作中有没有过度曝光衍射花样的操作？如果有的话，什么时候需要进行这样的操作？谢谢各位大牛！