How to Properly Focus a Microscope With Correct Light Levels
- 1). Lower the microscope stage away from the lens using the coarse focus adjustment. The side of the microscope will have a large knob (coarse focus) and a small knob (fine focus).
- 2). Rotate the objective lens so that the lowest powered objective (4x) is selected.
- 3). Place a slide on the stage and adjust the slide so that the specimen is in the light beam.
- 4). Look through the eyepiece and begin to adjust the coarse focus until the specimen comes into view.
- 5). Adjust the fine focus until your view of the specimen is clear.
- 6). Adjust the light diaphragm found under the microscope stage. Twist the diaphragm to the left or right to allow more or less light onto the specimen. Continue until you find the light level that allows you to see the greatest level of detail.
- 7). Rotate the objective lens to the next level of magnification. The specimen should still be in focus. If it is not, adjust only the fine focus. Adjusting the coarse focus can cause the lens to break through the microscope slide. Readjust the light diaphragm if necessary.