How to Use the High‑Power Objective of a Microscope
① Select the target
Center the region to be observed under the low‑power objective and focus to obtain a clear image before switching to high‑power observation.
② Rotate the nosepiece to switch objectives
Turn the nosepiece slowly to shift to the high‑power objective. Observe from the side during switching to prevent the high‑power lens from striking the slide. If the high‑power objective hits the slide, the low‑power focus was not properly adjusted, and the operation must be restarted.
③ Adjust the focus
After switching to the high‑power objective, observe through the eyepiece with your left eye. At this stage, the image is usually blurry. Turn the fine focusing knob clockwise by about 0.5–1 turn to get a sharp image. Do not use the coarse focusing knob.If the brightness of the field of view is inappropriate, adjust it with the condenser and diaphragm. If you need to replace the slide specimen, rotate the coarse focusing knob clockwise to lower the stage before removing the slide. To magnify the image, move the specimen closer to the objective; to reduce the magnification, move it farther away.
Notes
When carrying the microscope, hold the arm with your right hand and support the base with your left hand. Never lift it with one hand, to avoid lenses falling off or collision. Place it gently, not at the edge of the bench; position it about 10 cm from the edge to prevent it from falling.
Only lens paper can be used to clean the optical and illumination parts of the microscope. Do not wipe them with handkerchiefs or cloth. Mechanical parts may be wiped with a soft cloth. Do not touch the lens surfaces with water drops, alcohol or other chemicals. If contamination occurs, clean it with lens paper.
When placing a slide, align the specimen with the aperture and do not tilt the slide, to avoid crushing the coverslip or damaging the specimen. Develop the habit of keeping both eyes open: use the left eye for observation and the right eye for drawing. Do not remove the eyepiece arbitrarily, to stop dust from entering the lens barrel. Do not disassemble any components to prevent damage.
After use, return the microscope to its storage cabinet following these steps: remove the slide, rotate the nosepiece to move the objective away from the aperture, lower the stage, lay the mirror flat, lower the condenser (do not let it touch the mirror), close the iris diaphragm, push the stage back, cover the microscope with a dust cover, and place it back in the cabinet. Fill in the usage log afterwards.
Note: The reflecting mirror should usually stand vertically. However, if the condenser is not raised to the proper height, the mirror may collide with the condenser when the stage is lowered, so the mirror is laid flat in this procedure.
