Numerical Aperture and Resolution: Understanding Microscope Performance

This lecture covers the relationship between Numerical Aperture (NA) and resolution in optical microscopy. It explains how increasing NA enhances resolution by reducing diffraction-limited spot size. The instructor discusses the impact of NA on capturing diffraction orders and presents examples of resolution improvement with oil immersion objectives. The lecture also delves into the effective NA influenced by condenser aperture, emphasizing its role in system resolution. Historical examples, including the 1888 Zeiss catalog images of diatoms, illustrate the significance of NA in achieving high resolution. Furthermore, the lecture explores super-resolution microscopy advancements, such as STED microscopy, and showcases bio-imaging with STORM for sub-diffraction imaging of microtubules.