What is Kohler illumination?
Kohler illumination is a method of adjusting a microscope in order to provide optimal illumination by focusing the light on the specimen. When a microscope is in Kohler, specimens will appear clearer, and in more detail.
Process of setting Kohler
- Specimen slide (will need tofocus under 10× power)
- Compound microscope.
- Mount the specimen slide onthe stage and focus under 10×.
- Close the iris diaphragm completely.
- If the ball of light is not in the center, use the condenser centering screws to move it so that it is centered.
- Using the condenser adjustment knobs, raise or lower the condenser until the edges of the field becomes sharp (see Figure 797.1 and Figure 797.2).
- Open the iris diaphragm until the entire field is illuminated.
When should you set/check Kohler?
- During regular microscope maintenance
- After the microscope is moved/transported
- Whenever you suspect objects do not appear as sharp as they could be.