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Köhler
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Köhler illumination is a microscope alignment technique that ensures images are evenly illuminated and at maximum resolution. The microscope should be adjusted for Köhler illumination before transmitted light imaging, phase contrast and differential interference contrast (DIC).
Before adjusting for Köhler illumination you need to know where the relevant condenser components are on the microscope. This varies between manufacturers and models. The image below gives some examples of where to find the field diaphragm, iris aperture, etc. If in doubt, please ask a member of light microscopy staff or see the helpful links at the bottom of the page.
Condenser adjustment for Köhler illumination
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