Introduction to the Binocular Microscope

BIOL 1151

Topics covered

Parts of a compound binocular microscope

How to care for a microscope.

How to focus a binocular compound microscope.

Parts of a microscope

Eyepiece

Arm

Nosepiece

Stage

Base

Parts of a microscope: Eyepieces

Binocular eyepieces

Telescoping eyepiece

Parts of a microscope: Nosepiece

turret

objectives

Parts of a microscope: Stage elements

Stage clip

Aperture (below)

Stage adjustment knobs

Backwards and forwards

Side to side

Parts of a microscope: Power, light, and focus

Power switch

Light adjustment wheel

Power cord

Coarse focus

Substage lamp

Fine focus

Care of microscope

Carrying a microscope: one hand grabs the arm and the other hand supports the bottom of the base.

Lens careDO NOT TOUCH THE LENS! The oil from your

hands can etch the glass.CLEAN THE LENS WITH LENS PAPER ONLY!

Other paper has fiber that can scratch the lens.Putting away the microscope: rotate to the 4X

objective and roll the nosepiece away from the stage so that the space between the stage and nosepiece is at a maximum.

Focusing a microscope

1. Rotate the turret so that the 4X objective clicks into place.

2. Place the slide on the stage. Pull out the slide clip, slip the slide in place and gently release the slide clip. The slide should be held under tension in place.

3. Center the specimen over the aperture.4. Using the coarse focus raise the stage until you reach

a stop. Watch from the side to make sure that the objective does not

smash into the slide!

5. Look through the right eyepiece only and lower the stage using the coarse focus until the specimen is focused. NEVER RAISE THE STAGE TO FOCUS!

Focusing a microscope

6. Adjust with the fine focus knob until specimen is sharp and clear.

7. Now adjust the binocularity by rotating the eyepieces so that they match the distance between your eyes and you see one circle with both eyes.

8. Cover your left eye and bring the specimen in focus with the fine focus knob.

9. Cover your right eye and adjust the sharpness by rotating the telescoping knob on the eyepiece.

10. Your specimen should be in focus for your eyes.

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Lenses

focus light rays at a specific place called the focal point

distance between center of lens and focal point is the focal length

strength of lens related to focal lengthshort focal length more magnification

Magnification and resolution

Magnification is the enlargement of a specimen. To determine magnification you take the power of the eyepiece X the power of the objective. Example: A 10X eyepiece and a 4X objective magnifies

the specimen 40X.

Resolution is the amount of detail you can see. This is limited by the wavelength of light that illuminates the specimen.

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