Steph's Nature and Science

A Resource for Middle School Science

The Microscope

Parts of the Microscope

How Much are you Magnifing By?

You have 2 lens that you are looking through in a micoscope.

Lens 1: The Eyepiece

Makes things look 10X times bigger

 

Lens 2. The Objective Lenses

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We have three different objective lenses but we can only use one at a time.

Our objective lenses can do 4X, 10X, and 40X.

To figure out how much total magnification you see, use multiplication.

The x next to the number means how many "times" it is magnified.  For example, 40x reads as "forty times" which means that the image you are looking at is 40 times bigger then in real life.

	Objective	Eyepiece	Total Magnification
Low Power	4x	10x	40x
Medium Power	10x	10x	100x
High Power	40x	10x	400x

Every picture that is drawn or photographed should be marked with the magnification!

 

Focusing a Microscope

1. Make sure you are using the lowest power objective lens (that would be the shortest one)

2. Use only the Coarse Adjustment (large knob)

3. Raise the stage until it almost touches the lens

4. Center the object in the middle of the circle of light (use your hands to move the object around)

5. Use the Coarse adjustment knob to lower the stage until the object is in focus

** If you cannot find the object or focus on the first try then repeat steps 1-5.

*** After you complete steps 1-5 with an object in focus then you may use a high power objective

DO NOT USE THE COARSE ADJUSTMENT KNOB WITH HIGH POWER OBJECTIVES!!!

 

What You See Changes

 

How to See

 

What You Are Looking For

Lets say you want to see a leg of a insect under a higher power.

Right now it is off to the right in low power.

Move the slide until what you want to see is in the center.

Then move your objective to a higher power and refocus using the fine adjustment knob.