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Examining a variety of cells using a light microscope, by digital technology or by viewing a simulation.

The magnification of a microscope tells you how much bigger and image is than the real object. For example if you’re on a magnification x10, then the image you see is 10 times larger than the actual specimen. 

In most cases the eye piece (ocular lens) magnifies the image by 10.

The weakest object lens magnification is 4, then 10 magnification and a max of 40 magnification. Some compound microscopes can have objects of 100 magnification, making an object appear 1000 times larger!

Scroll over each magnification below, to see what Elodea looks like at different magnifications. 

Notice as the magnification increases, the amount of the specimen you see decreases. 


Elodea - 40 x

4 (objective lens) x 10 (eye piece) = 40 times the original image

Elodea - 100 x

10 (objective lens) x 10 (eye piece) = 100 times the original image

Elodea - 400 X

40 (objective lens) x 10 (eye piece) = 400 times the original image

Since things you see under a microscope are so small, we measure them in micrometres (μm). 1 μm is one-thousand of a millimetre.  

So, how can we can calculate the length of a magnified object under a microscope? 

Length of object = length of magnified object / magnification

For example, if a specimen looked 10mm in length under a microscope at a magnification of 1,000 times, the calculation of the actual length would be:

Length of object = 10 ÷ 1000 = 0.01 mm

Now that we have a length in millimetres (mm) we need to convert it to micrometers (μm). Multiply this number by 1000. 

Unit of lengthConvert byTo
Kilometers (km)x1000Meters (m)
Meters (m)x100Centimetres (cm)
Centimetres (cm)x10Millimetres (mm)
Millimetres (mm)x1000Micrometers (μm)
Meters (m)÷1000Kilometers (km)
Centimetres (cm)÷100Meters (m)
Millimetres (mm)÷10Centimetres (cm)
Micrometers (μm)÷1000Milimetres (mm)

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