why are images observed under the light microscope are reversed and inverted
The observation of reversed and inverted images under a light microscope is a result of how the microscope lenses and the eye work together to magnify the specimen.
To understand why this happens, let's first discuss how a compound light microscope works. A compound light microscope consists of two sets of lenses - the objective lens and the eyepiece lens. The objective lens is located closer to the specimen and has a higher magnification power, while the eyepiece lens is closer to the eye and provides additional magnification.
When light passes through the objective lens, it converges to form an inverted, magnified real image of the specimen. This real image is then further magnified by the eyepiece lens, allowing us to observe a larger image of the specimen.
However, since the real image formed by the objective lens is inverted, the final image observed through the eyepiece lens will also be inverted. This means that the top of the specimen will appear at the bottom of the observed image, and vice versa.
Additionally, the objective lens also produces a laterally inverted image. This means that the left side of the specimen is observed on the right side of the image, and the right side is observed on the left side. This effect is due to the way the objective lens refracts (bends) the light passing through the specimen.
Now, when we combine the inverted image from the objective lens and the laterally inverted image due to refraction, we end up with a final image that is both reversed and inverted compared to the original specimen.
To overcome this, some microscopes can include an additional lens called a "Bertrand lens" or "Ploem lens" between the objective and the eyepiece. These lenses can correct for the inversion caused by the objective lens, resulting in a non-reversed image.
In summary, the reversal and inversion of images observed under a light microscope are consequences of the way light is refracted and magnified by the objective and eyepiece lenses. Understanding this helps us interpret the observed images accurately.