Why Are Images Upside Down Under a Compound Microscope?

Compound Microscopes

Compound microscopes have more than one lens and commonly contain multiple objective lenses as well as an eyepiece lens. The objective lenses are on the microscope's nosepiece and can be rotated into place depending on the magnification desired. The ocular lens, or eyepiece, is at the top of the microscope where the eyes are placed. Both the objective lens and the ocular lenses are convex. This means that light rays that pass through will come together at a central point, referred to as the focal point.

Why Do Specimens Appear Upside Down?

In order to obtain high magnification images of a specimen, the objective lenses have very short focal lengths. Once light passes through a specimen, it will pass through the objective lens. After the light passes the focal point, an upside-down and magnified image of the specimen is formed. The upside-down image is the object that the eyepiece lens further magnifies.

Implications

Although the image seen through the compound microscope is upside down, it still allows the specimen to be studied. In many research laboratories, microscope images are viewed on a computer screen and can easily be adjusted so they are viewed as right-side up.

References

• The Compound Microscope