Microscopes – A Complete Guide

Microscopes are familiar instruments, commonly found in laboratories around the world. They are used to magnify and examine objects and details which are often too small to see with the naked eye.

Microscopes use varying methods to magnify small objects and details, usually for scientific or industrial purposes.

The most widely used design is the optical microscope which directs light through a carefully calibrated combination of lenses with varying focal lengths. These curved pieces of glass or plastic then bend that light, spreading out the rays emitted by tiny objects under examination in order to generate a magnified image.

However, this is just one example and other types of microscope use entirely different methods to produce much more powerful magnification. We will cover some of the additional microscope types in the following section.

There are four principal types of microscope. These are:

Optical/Compound Microscopes

Main Benefits :

• The most common type of microscope
• Features eyepieces to view imagery

Ideal Applications :

• Microelectronics, biotechnology, microbiology, education

Stereo Microscopes

Main Benefits :

• Two eyepieces as standard
• 3D viewing

Ideal Applications :

• Studying solid objects, close work such as surgery or dissection, botany, working with electronics

USB Microscopes

Main Benefits :

• Portable plug-and-play functionality
• Imagery displayed on a PC screen

Ideal Applications :

• Examining flat objects and printed circuit boards, scientific research requiring the observation of moving objects such as microorganisms

Electron Microscopes

Main Benefits :

• High magnification and resolution
• Exceptional quality imagery

Ideal Applications :

• Scientific applications, studying biological and inorganic objects, industrial purposes including failure analysis and quality control

Let’s take a look at each type in more detail.

Compound Microscopes

The optical microscopes familiar from education and scientific laboratories are technically known as compound microscopes. This is because they combine two or more lenses to generate a magnified image. This distinguishes compound microscopes from simpler, single-lens microscopes – a category which includes magnifiers.

The main lenses within a compound microscope are:

• Objective Lens – directly above the glass slide on which the object under examination will be placed
• Ocular Lens – this is more commonly known as the eyepiece

These are both convex lenses, meaning that they curve outwards. In more complex models, both the objective and the ocular lens may consist of multiple lenses linked together.

See for Yourself!

Take a look at our video to see the key features of the RS Pro Wi-Fi microscope and how it works.

These handheld digital microscopes feature built-in Wi-Fi transmission, enabling a seamless transition from instrument to screen. Wi-Fi microscopes offer a high degree of flexibility and greater functionality compared to alternative types, allowing the user to measure, copy, and transfer both images and video in real-time.

Electron Microscopes

Electron microscopes make use of an accelerated beam of electrons to generate an image of the object under examination. The image is produced as each electron bounces back onto the device’s specialist lens. Since they do not rely on conventional lenses, electron microscopes can produce images with significantly greater magnification and resolution.

Electron microscopes are typically powerful, high-end devices primarily used in scientific settings. There are two key types – SEM (scanning electron) and TEM (transmission electron). The former produces a 3D image and the latter produces a 2D image.

X-ray microscopes also work on a similar principle, using electromagnetic radiation to produce magnified images.

Microscopes are widely used in laboratories and similar environments by professionals in a variety of scientific fields, including:

• Geology
• Biology
• Botany
• Medicine
• Forensics
• Chemistry

Microscopes are also used in industry – for example, pharmaceutical manufacturing and engineering. In addition, they are a common inclusion in education environments including school and university laboratories.

In each case, microscopes are used to examine fine details invisible to the naked eye or objects too small to be seen otherwise. This could include microscopic organisms, plant and animal cells, and chemical structures, to name just a few examples.

To cater to such a wide range of applications, microscopes are produced in different shapes and sizes, ranging from larger designs to light, portable handheld models.

The magnification strength of a microscope varies between different models. Standard compound microscopes typically magnify objects by either 10, 20, 40, 100, or 400 times, but industrial models can generate images which have been magnified over 1,000 times. Some electron microscopes can take that even further, providing up to as much as 10 million times magnification.