- Completely close the condenser aperture diaphragm when starting to use the microscope.
- Rotate the low power objective into position and find the focus with the coarse focus knob. The larger depth of field and higher contrast makes it easier for the students to focus the specimen.
- When switching to a higher magnification, the students should start to gradually open the condenser aperture diaphragm, to observe the differences in image quality.
- Adjust the light intensity with the dimmer to prevent glare. Students should be made aware that the condenser aperture diaphragm should be adjusted to the numerical aperture value which is printed on the objective.
- Opening the diaphragm further will not increase image quality, but may result in glare. If the sample is thick, strongly stained or pigmented then the diaphragm has to be opened to allow more light to pass through the specimen. As a consequence, the depth of field becomes smaller.
- Use the fine focus adjustment knob to focus through the different layers of the specimen
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