Parts of a Microscope and their Functions

Ocular Lens

Eyepiece which contains a lens to magnify an image 10x that projected by the objective lens.

Body Tube

Connects the Ocular Lens to the Objective Lenses and provides alignment to direct the light from the specimen into the viewer's eye.

Arm

Connects the body tube to the base. One hand should be around this when carrying a microscope.

Coarse Adjustment Knob

First knob you should use and always under low power, makes large adjustments to the focus. Should never be used in high power.

Fine Adjustment

The second knob you should use under higher power for exact focusing.

Rotating/Revolving Nosepiece

Holds the objective lens and can be rotated to change the magnification.

Objective Lenses

Adjustable lens system that permits the use of a low power lens, a medium lens, or a high power lens

Low Power

This objective lens provides the lowest magnification, 4 x

Medium Power

This objective lens provides a medium magnification, or power, 10x

High Power

This objective lens provides the highest magnification, 40x

Stage

Where you place the slide containing the specimen; It contains a hole that allows light to pass through the stage and onto the specimen.

Stage Clips

Holds the slides in place on the stage for viewing.

Diaphragm

It contains a dial that rotates to adjust the amount of light that reaches the specimen and is passed upwards towards the eyepiece.

Base

Supports the weight of the microscope. Contains the electronics and the light source.

Light Source/ illuminator

An electric source of illumination or a mirror used to direct light upward.

Condenser Lens

The lens under the stage that focuses light from the illuminator through to the hole in the stage

How to carry a microscope

Always carry the microscope by:

the arm with the other hand supporting the base

Total Magnification =

Ocular Lens Magnification x Objective Lens Magnification