1. Place a slide on the stage and turn on the microscope with the switch on the front.
2. Adjust the eyepiece until only one circle is seen.
3. Adjust brightness with the slider on the right side and set the objective lens to 10x by rotating the turret that the lenses are attached to.
4. Raise the stage (1.) using the coarse focus knob until the slide is as close to the objective lens as possible without touching it. Now, look through the microscope while turning the coarse focus knob towards you (2.) to bring the stage down and the image into focus.
5. Adjust the aperture diaphragm so the setting matches that of the objective's numerical aperture.
6. Close the field diaphragm all the way down.
7. Focus the condenser using the knob to the left of the aperture diaphragm until a small octagon appears (so that it looks like the above right image.)
8. Center the field diaphragm in the field of view using the two metal knobs right below the front of the stage.
9. Open up the field diaphragm until its edges are just outside of the frame.