What is the main purpose of Koehler illumination in microscopy?

The main purpose of Koehler illumination in microscopy is to center the light source and spread light uniformly over the field of view. This technique optimizes the illumination of the specimen, ensuring that the light is distributed evenly across the entire area being observed. By achieving this uniformity, Koehler illumination enhances the quality of the image, reduces glare, and minimizes artifacts that can result from uneven lighting.

This method involves aligning the light source with the optical path, and it ensures that the light is adequately converged and positioned. As a result, it allows for better resolution and clarity of the specimen, enabling accurate observation and analysis. The consistent and bright illumination helps in visualizing fine details in the sample, making it an essential technique in microscopy.