Understanding the Microscope

UNDERSTANDING THE MICROSCOPE

UNDERSTANDING MAGNIFICATION A microscope’s power refers to the amount of

magnification.

Power can be computed if you know the magnification of the eyepiece lens and the objective lens.

WHAT’S MY POWER? To calculate the power of magnification,

multiply the power of the eyepiece lens by the power of the objective.

x What’s my power?

TOTAL MAGNIFICATION: TO FIGURE THE TOTAL MAGNIFICATION OF AN IMAGE THAT YOU ARE VIEWING THROUGH THE MICROSCOPE IS REALLY QUITE SIMPLE. TO GET THE TOTAL MAGNIFICATION TAKE THE POWER OF THE OBJECTIVE (4X, 10X, 40X) AND MULTIPLY BY THE POWER OF THE EYEPIECE, USUALLY 10X.

4x objective lens 10x eyepiece

10x objective lens10x eyepiece

40x objective lens10x eyepiece

COM

PARING

POW

ERS OF M

AGN

IFICATION

What is the difference between magnifications?

We can see better details with higher the powers of magnification, but we cannot see as much of the image.

Which of these images

would be viewed at a

higher power of

magnification?

WHY ARE THE IMAGES NOT WHAT I WOULD EXPECT?

Letter “E”

WHY?LIGHT TRAVELS IN A STRAIGHT LINE, BUT WHEN IT PASSES THROUGH THE MAGNIFYING LENS, IT REFRACTS (CHANGES DIRECTION), CAUSING THE IMAGE TO BE UPSIDE DOWN AND BACKWARDS. THE FINAL IMAGE FORMED BY THE EYEPIECE LENS IS REVERSED AND MUCH LARGER THAN THE OBJECT BEING VIEWED.

Image you see in the microscope is…

Reversed (flipped left to right)

and

Inverted (flipped top to bottom)

WHAT DOES THIS MEAN FOR YOU? When you nudge the slide you are studying

away from you, the image will move towards you.

When you push the slide a bit to the left, it will move to the right.

SHOULD WE TRY IT?What do I do when I get a turn at the microscope?What should I do while I am waiting for a turn?

Have your partner read through the steps while you perform the operations. When you are done,

switch roles.

~Steps for Microscope Viewing~1. Start with the lowest power objective lens.

2. Place your specimen on the middle of stage.

3. Use the coarse adjustment knob to bring the objective lens close to the slide.

4. Use the fine adjustment knob to focus the object.

5. Rotate the objective lens to a higher power and use the fine adjustment knob again.

6. Record your observations.Remember: Record exactly what you see.

7. Finished? Switch back to the lowest objective lens

8. Turn off the light.

WHAT DO I DO WHILE I AM WAITING FOR MY TURN? Review the parts of the microscope Cut out the vocabulary cards for the parts of a

microscope Challenge yourself to a game of concentration There will be a quiz on the parts of the

microscope soon

Students will be called back in pairs to view the “e” slides…listen carefully for your names

Unsafe or improper behavior = immediate loss of privilege