原文由 xinghui82 发表:
我们这台2100F在衍射模式下用物镜光阑套住透射斑点或某一衍射斑点准备做明(暗)场象时,当转换到成像模式后(撤去选区光阑),惊奇地发现仍然会出现若干类似衍射斑点的光斑,而明(暗)场象就出现在中心一个斑点中。这种现象难以理解,可是合轴对中我们已做的很好,物镜光阑也在衍射模式时将边缘聚焦清楚。那位高手帮忙看看问题可能出在哪里?
It is a really strange phenomenum. But the strange image was on screen or on CCD image?
we had some experiences that when the intensity of TB(transmitted beam) was too strong, there was some residual intensity on CCD image.
If the image was on screen, that is unreasonable. The function of the "image" button is to choose the focal length of the intermediate len between image and backfocal planes(DP).