Chapter 3 Detailed Explanation
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3.4 Operating the Nosepiece and Objectives
3.4.1 Switching
Objectives
To switch objectives to use for observation, manually turn
the turret ring of the nosepiece right or left until it reaches
the click position.
Objectives are usually set in such an order that the
objective magnification increases as the nosepiece is
turned clockwise (as viewed from the top of the nosepiece).
When light intensity management is on
When the light intensity management function is
turned on (LIM), bringing the objective into the
optical path loads the memorized brightness.
Operating the nosepiece
3.4.2 Oil-Immersion
Observation
The “Oil” mark on the side of an objective indicates that it is an oil-immersion type objective. (The
oil-immersion objective also has a black band around the barrel end.) An oil-immersion objective is used with
the immersion oil applied between the front of the objective and the coverglass.
For an oil-immersion objective with a numerical aperture of 1.0 or more, also apply immersion oil to the
condenser to take full advantage of its performance. (An oil-immersion type condenser needs immersion oil to
be applied between the front of the condenser and the specimen.)
The condenser has an oil receptacle around the front of its lens.
Example of oil-immersion
Apply immersion oil to the condenser and then objective.
• Condenser:
Add a drop of oil on the condenser lens, and then place the specimen on the stage.
• Objective:
Rotate the revolving nosepiece to move the objective out of position. Add a drop of oil to the specimen.
Slowly rotate the revolving nosepiece to bring the objective back into position.
Eliminating air bubbles
Make sure that air bubbles are not trapped during oil application. Air bubbles degrade the image.
Do any of the following to eliminate air bubbles:
•
Rotate the revolving nosepiece to move the objective back and forth once or twice.
•
Add another drop of oil.
•
Wipe off the oil and apply again.
