Kohler Illumination

Steps to Kohler Illumination:

Step 0: Make sure the lenses, eyepieces, and objectives are clean. 

Step 1: Close the field diaphragm so you see a small circle of light

Step 2: Focus the condenser so that the small circle of light has solid lines. In some cases, the circle of light may become a polygon.

Step 3: Center the condenser as best as you can (this can sometimes be tricky).

Step 4: Open the field diaphragm until the edges of the circle of light dissapear. The edges of the circle should be just outside your field of view.