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

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

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

14. Modern Compound Microscope
Definition of a Compound Microscope : an instrument for magnifying small objects, consisting of a lens of short focal length for forming an image that is further magnified by a second lens of longer focal length Compare

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

17. 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.

18. 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.

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

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

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

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

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

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

25. → 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 →

26. → Fine Adjustment Small, round knob on the side of the microscope
Used to fine tune the focus after using the coarse adjustment knob. →

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

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

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

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

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

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

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

39. 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 ← ← ← → ←

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

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