A microscope is optical equipment utilized to picture an object onto a video device or human eye. Old days’ microscopes consisted of two elements that generated a bigger image of an object under examination than what human eyes could detect. The technique has developed over the microscope’s history to now integrate filters, lenses, polarizers, sensors, beamsplitters, illumination sources, and a host of other elements. One must consider a microscope’s objective, components, key specifications, concepts, and applications to deduce these intricate optical tools.

The microscope objective lens is the ones placed at the bottom near the sample. It is an extremely high-powered amplifying glass having a very short focal length. Users need to bring in very close to the specimen being analyzed so that the light from the sample arrives in the focus of the microscope tube.

Power of a microscope

Most of the compound microscopes are found with exchangeable lenses called objective lenses. One can find the objective lenses in several magnification powers. The most general types are 4x, 10x, 40x, and 100x, or they are called scanning, high power, low power, and oil immersion objectives, respectively.

What are the four objectives of a microscope?

The microscope objective allows it to deliver real and magnified images. These are perhaps the most complex element in a microscopic system for their multi-element structure. Objectives are accessible with magnifications that range from 2X – 200X. These are classified into two major categories, namely the refractive and reflective types. Each of the categories is subdivided into finite conjugate and infinite conjugate types. To select the precise objective, it is crucial to learn the advantages of one category and variety from another.

The most popular category of objectives is refractive, where light passed through the process is refracted or tilted by the optical components.

On the other hand, the reflective objective utilizes a reflective or mirror-based design.

The microscope objectives are of 4 types. These are Scanning (4x), High (40x), Low (10x) and Oil Immersion (100x). To perceive microorganisms, the oil immersion lens is required together with technical instructions that are not covered in this method.

Functions of Microscope

The objective placed closest to the object transmits a real object image to the eyepiece. The portion of the microscope is required to generate the base magnification. The real image is magnified and projected by the eyepiece found closest to the sensor or eye, and it produces a virtual image.

Size of Microscope

The focal length of a microscope objective is generally between 2 mm and 40 mm. However, that parameter is often deemed significant since numerical aperture and magnification are enough for quantifying the necessary operation of a microscope.


To clean the objective lenses, one needs to place the objective lens on a clean surface. Blowing away loose dust from the surface of the optical glass with a dust blower is necessary. Any dust left on during the cleaning procedure may scratch the coating or optical glass.