1. Introduction to Microscopes!
Now Seeing IS Believing!

2. A Brief History

3. Simple Glass Magnifiers
More than 500 years ago.
In 1600s, this “simple microscope” allowed scientists to see cells and bacteria
Problem: not enough magnification

4. First Compound Microscope
Developed at the beginning of the 1600's, by the Janssen brothers and Galileo
Problem: images were blurred and had colored halos

5. Simple Compound Microscope
Invented in 1660s
Problem: all images had red or blue “halos” around them

6. Even better! 1700 and 1800s – great improvement in microscopes
Usually made of brass (expensive)
Had a tripod for support

7. Modern Compound Microscope
1900s, started using iron instead of brass (cheaper)
Only one eyepiece (monocular)
Outside light source reflected onto mirror
Very functional
Still used today

8. Fancy! Better images More magnification Better lighting Easier to use
Now everyone, at one time or another, has looked through a microscope

9. How Does It Work? A microscope works very much like a telescope.
A telescope must gather light from a dim, far away object.
So, it needs a large objective lens to gather as much light as possible and a long body to bring the image into focus.

10. How Does It Work?
Unlike a telescope, a microscope must gather light from a tiny specimen that is close-by.
So the microscope does not need a large objective lens.
Instead, the objective lens of a microscope is small.
Then the image is again magnified by a second lens, called an eyepiece, as it is brought to your eye.

11. Parts of a Compound Microscope
So EASY a KID could use it!

12. ← Base The bottom of the microscope, used for support
Hold this part with one hand when carrying a microscope ←

13. Mirror
Reflects the light so the specimen is easier to see ←

14. ← Stage The flat platform where you place your slides.
It has a hole in it so light can shine through ←

15. Clip
Shiny clips on the top of the stage
Holds a slide in place ←

16. ← Arm Supports the tube and connects it to the base
The part you hold when you carry the microscope ←

17. → Coarse Adjustment Large, round knob on the side of the microscope
Either moves the stage or the top part of the microscope up and down
Use only on Low Power →

18. → Fine Adjustment Small, round knob on the side of the microscope
Used to fine tune the focus after using the coarse adjustment knob.
Use on all Objective lenses except Low Power →

19. Eyepiece →
The lens at the top that you look through.
10X power

20. Body Tube
The long tube that holds the eyepiece and connects the objective →

21. Nosepiece
Rotating part of the microscope at the bottom of the body tube.
It holds the objective lenses ←

22. → High Power Objective The longest objective lens
The highest magnification
40X lens (40X x 10X = 400X magnification) →

23. ← Low Power Objective The shortest objective lens
The lowest magnification
4X lens (4X x 10X = 40X magnification) ←

24. ← Mid Power Objective The medium length objective lens
The medium magnification
10X lens (10X x 10X = 100X magnification) ←

25. Diaphragm
Controls the amount of light going through the hole in the stage →

26. Pop Quiz
What two parts should you hold when you carry a microscope?
Base & Arm
Where do you put a slide?
On the Stage
To focus, what knob do you turn first? Second?
First, Coarse Adjustment
Second, Fine Adjustment ← ← ← → ←

27. Test Your Skills . . . Arm Body Tube Stage Clip Base Coarse Adjustment
Fine Adjustment

28. Test Your Skills High Power Objective Low Power Objective Mirror
Eyepiece
Nosepiece
Diaphragm