The Light Microscope

The Light Microscope
In the 1590’s Zacharias and Hans Jansen, were working on spectacles’ production, and started playing with the lenses. They found that images were enlarged by looking through the lens. Anton van Leeuwenhoek was the man that then developed this idea, and created the first microscope. His microscope could magnify up to 270x, whereas Jansen’s lens could only magnify up to 9x. (HISTORY OF THE MICROSCOPE, 2010)
Leeuwenhoek’s work allows us to widen our knowledge in many areas of science, such as, “basic biology, biomedical research, medical diagnostics and materials’ science.” (HOW STUFF WORKS, 2013)
Figure 1 is a light microscope (commonly known as LM).

Figure 1: A compound light microscope (LEAVINGBIO.NET)

A light microscope is very similar to a telescope in the way that it works. A LM, “gathers light from a tiny area of a thin illuminated specimen that is close-by, so the microscope doesn’t need a large objective lens.” (HOW STUFF WORKS, 2013) Hence why the objective lenses are interchangeable and are typically 4, 10 and 40 magnifications.
The specimen has to be stained, so that it is visible under the light microscope. If the specimen is not stained, it makes it very difficult to see what is actually on the slide in the microscope.
Next, by a second lens, known as the eyepiece, magnifies the image even further and brings the image to your eye.
Particularly with a LM, a graticule can be added into the microscope. This is a miniscule ruler that is attached in the eyepiece. Thus, the actual sizes of the image can be worked out through the Image-Magnification-Actual (IMA) triangle below, figure 2.

From this diagram, we can see that the magnification is the image size divided by the actual size of the object.
In addition, the actual size of the object seen under the microscope can be worked out by dividing the image