Indian Institute of Science (IISc)

Demo 01

Demonstration on optical microscope

  By Om Prakash

Tunable structural colouration


Welcome to our demonstration on Kohler illumination for transmission optical microscopes! Kohler illumination is a technique used to optimize the lighting in a microscope, ensuring uniform and bright illumination of the specimen. In this demonstration, we will show you how to set up Kohler illumination on a transmission optical microscope and explain its importance in achieving high-quality microscopy images. We will start by adjusting the microscope's light source to produce a well-defined and evenly illuminated field of view. Next, we will demonstrate how to center the condenser aperture diaphragm to ensure that only the central portion of the light beam reaches the specimen. This step is crucial for reducing stray light and increasing contrast in the image. Finally, we will show you how to adjust the field diaphragm and the Kohler illumination is achieved when the specimen is evenly and brightly illuminated, enhancing the clarity and contrast of the images. Join us as we explore the world of microscopy and learn how to achieve optimal illumination for your microscopy studies.