Microscopes

1. Microscopes

2. The First Microscope
• The first microscope was created by
Zacharias Janssen
• For millennia, the smallest thing humans
could see was about as wide as a human
hair. When the microscope was invented
around 1590, suddenly we saw a new world
of living things in our water, in our food and
under our nose.

3. The Compound Light Microscope
• Light passes through the specimen
• Lenses enlarge or magnify the image
• Micrometers (μm) are used to measure very
tiny objects (1mm = 1000 μm)

4. Parts of the Microscope
Lowest magnification to highest

5. How to use a Microscope

6. Estimating Measurements
• Being able to estimate the size of an
object viewed under a microscope is
an important skill. It’s important to
understand Field ofView
• Field ofView: Field of view is the
diameter of the circular region of the
slide visible under the microscope

7. Estimating Measurements
• What will happen to the Field ofView
as we increase the magnification?
Why?
• As you increase the magnification the
FOV gets smaller (decreases).

8. Estimating Measurements
• If you knew the Field ofView (400 μm) of a
microscope, how could you estimate the
size of an object?
• You can divide the FOV by the number of
objects that would fit.
• Estimated size = FOV/#fit
• = 400μm/4
• =100μm
• 1mm = 1000μm
• So 100μm = 0.1 mm