This lecture covers the importance of setting up a correct transmission light path for confocal imaging to acquire additional structural information. The instructor demonstrates how to optimize the transmission light path by adjusting the field diaphragm, condenser height, and aperture diaphragm, ensuring a homogeneous TP-MT imaging. The process involves focusing the sample, narrowing down the illuminated field, adjusting the condenser position for sharp illumination, and setting the aperture diaphragm for contrast enhancement. The lecture emphasizes the significance of correctly configuring the transmission light path for improved imaging results.