1. The Compound Light Microscope
Parts of the light microscope
How to focus a light microscope

2. The microscope is a tool that extends vision and allows observation of very small objects.
Magnification – the increase in the apparent size of an object
Resolution – a measure of the clarity of an image, the ability of to show two objects as being separate

3. The micrometer is a unit used for microscopic measurement
1 millimeter (mm) = 1000 micrometers (μm)
Therefore, 3 mm = ______ μm

4. (Ocular lens)
Red -
Yellow -
Blue -

5. How to care for the microscope
Always carry with two hands
One on the arm & one on the base
Keep track of the cord when walking
Should be wrapped around the base
Use the dust covers when storing
Always return to where it was taken
Only use lens paper for cleaning the lenses
NEVER use a paper towel or your shirt

6. How to focus a light microscope
Turn on the light source and move the scanning (4x – Red) objective into working position.
Using the coarse focus knob, move the stage to the lowest setting it will go to.
Place the Paramecium slide on the stage, center the slide over the opening in the stage and secure with stage clips.
Look through the eyepiece and slowly bring the specimen into focus with the coarse focus knob (this raises the stage)
Move the slide to the center of your field of view as observed through the microscope.
What do you notice about
the movement of the slide?

7. How to focus a light microscope
With the object in focus as good as you can get it, use the fine-focus know to sharpen the image.
Now, carefully bring the low-power (10x – Yellow) objective into the working position.
Refocus the image using the fine-focus and, if needed, re-center the specimen in the field of view.
Next, carefully bring the high-power objective (40x – blue) into the working position.
Sharpen the image with the fine-focus knob ONLY, and move slide to center the object in the field of view.