What are the Types of Objective Lenses on a Microscope?

When talking about types of objective lenses we are referring to the different magnifications and purposes of the four most common types of microscopeobjective lenses on compound light microscopes.

Those four are:

The scanning lens (4x)

The low power lens (10x)

The high power lens (40x)

The oil immersion lens (100x).

Most compound light microscopes are sold with a 40x magnification high power lens, although this is not always the case. You may get a 32x or 60x magnification high power lens, for example. 

A 40x lens will achieve magnification of 400x when combined with a 10x eyepiece or 800x magnification with a 20x eyepiece. It is also very commonly used with 25x eyepieces to reach 100x magnification.

Oil Immersion Lens (100x) are called 'oil immersion lenses' because you usually need to use them with oil in order to view your specimen.

At higher magnifications achieved with a 100x lens, there will often be too much distortion in the final image. To address distortion at high magnification levels, you can use oil immersion.

A lens is an optical device that can reflect light. The reflection depends on the shape of a lens, which is typically convex or concave.

Convex lenses are used for their ability to focus light at a single point. Microscopes uses convex lenses to focus light towards a point that is distance away from the lens.

Lens shapes can be seen in Fig.2. It should be noted that these lenses are symmetrical and will have the same effect on light from either direction.

Microscope objective lenses can also be classified in several ways, including:

• By magnification
• By microscopy technique
• By lens shape
• By aberration correction
  

we will talk about the point next time.

Conclusion

As you can see, there are many different types of objective lenses on microscopes. This list is by no means exhaustive, but does outline the common objective types that you will find on a regular compound light microscope in a school or home setting.