Microscope: Operating Guide

General Use:
Make sure the microscope is placed on a flat surface. For first time use prepare a slide with a mark made by marker crayon or a sharpie marker. You may use this mark to learn to focus the microscope. To see how to carry a microscope mouse over the picture to the right.

1. Turn the revolving nosepiece to engage the 10X objective. Make sure that the revolving nosepiece stops with an audible click.

2. Lower the stage using the coarse adjustment and gently place a prepared slide on the stage in the specimen holder clips. The specimen holder clips are spring loaded and if forcibly released may break the slide.

3. Turn the X-axis and Y-axis adjustment knobs to move the mark on the slide into the light path. Do not move the stage manually without the adjustment knobs. There are limits to how far you can turn the knobs. Do not force the knobs.

Microscope X Adjustment:

Microscope Y Adjustment:

4. Switch the main switch to ON and adjust the brightness with the light intensity knob

Microscope Main Switch On:

Microscope Light Intensity Adjustment:

5. Looking through the right eyepiece with your right eye, turn the coarse adjustment knob to bring the specimen into focus. When you have optimized the focus with the coarse adjustment controls, use the fine adjustment knob to improve the focus.

6. Looking through the left eyepiece with you left eye, turn the diopter adjustment ring to focus the specimen.

7. Adjust the interpupillary distance between the eyepieces. Look through the eyepieces and manually adjust the space between the eyepieces until the left and right fields of view coincide completely.

  • Question
  • Answer

This ability to adjust the interpupillary distance for your specific eyes is one of the ways you can customize the microscope for your use. What is a second way you can customize the microscope?

It is possible to adjust the focus for vision differences between your two eyes. This is done using the diopter adjustment ring.


8. Center the field iris diaphragm by manipulating the two centering screws on the compensating lens. TALK TO YOUR INSTRUCTOR BEFORE CENTERING THE FIELD IRIS DIAPHRAGM.

9. Engage the pre-focusing lever by rotating it toward you. The lever ensures that the objective does not come in contact with the specimen and simplifies focusing. Engaging the lever sets an upper limit on coarse adjustment movement. Focusing with the fine adjustment knob is not affected by the lever. The microscope is designed to allow the microscopist to change the objective used to view the image with little or no focusing adjustments.

  • Question
  • Answer

Parfocal microscopes allow the microscopist to change the objective and view the specimen with minimal focusing, using only the fine adjustment knob. Why was the development of these microscopes important?

It is difficult, when looking though the eyepieces, to judge how close the objective is to the slide. With high power and oil immersion objectives it is possible for the slide or specimen to make contact and this could lead to damage of either the objective or the specimen.


10. Engage the objective to be used for observation by turning the revolving nosepiece. Refocus by rotating the coarse adjustment knob to reach the pre-focusing position, this is limited by the engaged pre-focusing lever. Make fine adjustments with the fine adjustment knob. Always focus "up", moving the objective away from the slide.

11. Adjust the light intensity to the desired level, and then readjust the fine focus.

12. Adjust the field iris diaphragm.

13. Adjust the aperture iris diaphragm. The iris aperture diaphragm controls the cone of light that reaches the objectives and therefore controls the numerical aperture. Matching the numerical aperture of the illumination system (given on the iris diaphragm) with that of the objective provides better image resolution and contrast, and also increases the depth of focus.

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