Light vs Electron Microscope: Which is Best for your Needs?

Last Updated: by: Robert Sparks

light vs. electron microscope

Not all microscopes are created equal, as any scientist will tell you.  But one of the biggest differences among microscopes is the mechanics between the light and electron types.  In fact, it’s probably a shorter answer to ask how the two microscopes are the same.  They’re both used for magnification, and they’re both used by scientists, medical professionals, and hobbyists.  But you’d be hard-pressed to find more similarities.  Read on to learn how vastly different these two devices are.  It should help you decide which would work better for you.

How Does a Light Microscope Work?

Light microscopes are smaller and more portable than electron scopes.  They create images by providing an artificial light source, which a small objective lens then absorbs.  The light is cast back into the device to a focal point, where an eyepiece lens gathers the image for viewing.  A microscope typically contains several objective lenses from which to select magnification power.  They also require that your specimen is somewhat translucent so light can pass through, and the specimen should be mounted on a glass slide.  For more opaque or larger specimens, a stereo microscope is more useful.  The stereomicroscope creates two offset axes of light that are then layered in the eyepiece to create a more three-dimensional image.

a light microscope

A light microscope from AmScope

How Does an Electron Microscope Work?

The larger, more cumbersome electron microscope doesn’t use any light to magnify its subject.  It uses pure fast-moving electrons, which are essential for viewing anything smaller than an atom.  The specimen must be placed in a vacuum since electrons don’t travel well through the air.  But this is where things get complicated.  In a transmission electron microscope (TEM), the electrons pass directly through the specimen onto electromagnetic coils beneath, which then form a computerized image.  In a scanning electron microscope (SEM), the electromagnetic coils bounce the electrons back and forth, creating a slow scan of the specimen.  Whatever electrons the specimen reflects are then captured on a screen.  Keep in mind that electrons don’t have color, though, so the results of an electron microscope will always be black and white.

electron microscope

An electron microscope. Credit: David J Morgan, Wikimedia

A Question of Power

Light

Light microscopes rely on light wavelength for magnification.  This means you’ll achieve up to 1000 times magnification, or up to 3 micrometers.  This level of power is ideal for educational or medical settings, especially since most specimens in these environments will contain living cells.  For larger specimens, the stereoscopic light microscope is more practical, although they’ll only achieve about 60 to 70 times magnification.

light

Image credit: D-Kuru, Wikimedia

Electrons

The use of electrons in an electron microscope means these devices achieve far more impressive results of up to 2,000,000 times magnification, or up to about 0.01 nanometers.  This makes the electron scope ideal for hard scientific research and specimen photography.  While TEMs produce only 2-D images and a smaller range, their resolution is superior.  SEMs produce 3-D images and can capture a larger range, but their resolution is less.

electron

Consider Your Specimen

Before you decide that nothing can beat an electron microscope’s power, consider what you’re planning to view under the lens.  A light microscope, while weaker, can look at living cells and moving specimens.  The specimens can be conveniently placed on a glass slide for viewing.  An electron microscope is more powerful, but the specimen must be dead and dried, or it won’t survive its encounter with electrons.  Electron microscope specimens are often coated in metal such as gold, as well, to aid in the reflection of electrons.  They also require a fluorescent screen, an electronic display, or a photographic plate to view them.

The Cost Factor

Light microscopes have a diverse market, from plastic pocket versions to the standard desktop models.  A decent light microscope, however, will range around $100 to $300, depending on its resolution and electronic capacity.  While electron microscopes are far more expensive, their use in the sciences makes them well worth their price point.  Lower-powered electron microscopes are available for home use for a few hundred dollars, but a legitimate, high-quality model will run between $3,500 to $20,000.

Which is Right for You?

Unless you’re planning to discover a new virus or study the finer points of pollen cells, a light microscope is perfect for home or personal use.  If your scientific pursuits require more power, head straight for the electron microscope.  But it’s possible you’ll have a need for both in your lab in order to capture specimens in either a living or dead state.  You’re likely to find thousands of uses for either microscope, but if your budget is tight, make sure you carefully weigh your new knowledge of these devices before diving in and making your purchase.

We’ve also written the post ‘How to choose a microscope you’ll love‘, which may help you in your search.

You can also read our overview of the 11 different types of microscopes that exist.