The Different Types and Uses of a Stereo Microscope

The Different Types and Uses of a Stereo Microscope

For an optical instrument that views larger, three-dimensional objects in great detail, read more to learn about the different types and uses of a Stereo Microscope.

What is a Stereo Microscope Used For?

Stereo Microscopes, also known as Dissecting Microscopes, magnify at low power and are designed to observe larger three-dimensional objects and specimens. There are multiple different types and uses of a stereo microscope, but they are generally useful for studying coins, minerals, insects, flowers, circuit boards and other electrical components, along with many other three-dimensional objects. They are also useful tools for engraving and watchmaking.

There are plenty of Stereo Microscopes to choose from. With manufacturers such as AmScope, Celestron, Zeiss, Saxon, Nikon and Olympus, there are many high-quality options available in Australia.

There are also quite a few different types of stereo microscopes, which we will cover in-depth later on.

How Does a Stereo Microscope Work?

Stereo Microscopes utilise two optical paths positioned at slightly different angles to accurately represent three-dimensional objects (MRC Laboratory of Molecular Biology, n.d.). To truly grasp how they work and understand how to use a microscope, we first need to explore the parts of a stereo microscope and their functions.

Parts of a Stereo Microscope and Their Functions

Refer to Figure 1 illustrating the parts of a stereo microscope.

Types and Uses of a Stereo Microscope: Labelled Diagram of the Parts of a Stereo Zoom Microscope and their Functions
Figure 1. Labelled Diagram of a Stereo Microscope

Eyepieces

Eyepieces (or Oculars) are where you look through to study specimens and objects. Stereo microscopes come in variants with one eyepiece (monocular head) or two eyepieces (binocular head). Binocular heads are superior to monocular heads as they use two eyepieces to display two images at slightly different angles, producing a sharper 3D image and improving contrast and depth perception.

Trinocular Head

A third design involves a Trinocular Head (optional), which is particularly useful if you intend to attach a Digital Microscope Camera to your microscope. A Trinocular Head features a binocular head with an additional camera port for photography, video recording or live streaming to an external device. This is discussed in more detail in later sections.

Objective Lens

Objective Lenses are the secondary lenses that allow the magnification of your microscope to be altered. Stereo Microscopes may have multiple objectives with different magnifications, which are normally selected on a rotating turret. Objectives generally range from 1x to 4x in magnification, depending on the microscope.

Zoom Knob

Existing only in Stereo Zoom Microscopes, the Zoom Knob of a microscope replaces the rotating turret, allowing for the magnification of the objective lens to be set more precisely. This is discussed in more detail further below.

Focus Knob

The Focus Knob (or Coarse Knob) raises and lowers the microscope head to adjust the focus of the object in view.

Sources of Illumination

Stereo Microscopes generally feature at least reflected, top-light illumination. Top illumination (upper illumination) is often combined with transmitted, bottom-light illumination (lower illumination) to enable the observation of objects under both a dark background and a bright background. These variations in light are termed dark field illumination and bright field illumination respectively (Chambers et al., n.d.).

Calculating Magnification

The eyepieces and the objective lens each have their own magnification. The total magnification of a stereo microscope is calculated by multiplying the magnification of these two values (Zeiss, n.d.).

For example:

3x objective magnification * 10x eyepiece magnification = 30x total magnification

Stereo Microscopes are generally able to produce a magnification between 10x and 50x.

Now that we have covered the parts and functions of a Stereo Microscope, read more to learn about the different types of stereo microscopes and their uses.

Types and Uses of a Stereo Microscope

Fixed Magnification Microscopes

Fixed Magnification Microscopes or Standard Stereo Microscopes allow the magnification of the objective lens to be selected with a rotating nosepiece or turret (Nothnagle et al., n.d.). Generally, these microscopes allow you to select between multiple fixed magnification settings. The Saxon PSB X1-3 allows you to set the objective magnification to either 1x or 3x, offering a total magnification of either 10x or 30x.

These microscopes are perfect for beginner observers, kids and families looking for a start in stereo microscopy.

Stereo Zoom Microscopes

Stereo Zoom Microscopes, Variable Zoom Microscopes or Zoom-Ratio Microscopes function slightly differently. Generally, these types of microscopes have an adjustable zoom knob that allows you to set a precise total magnification. Rather than set values (such as 10x and 30x), Stereo Zoom Microscopes allow for any magnification level to be used within a set range (Nothnagle, et al., n.d.). The Saxon RST Researcher Stereo Microscope 10x-40x is a Stereo Zoom Microscope that allows for any magnification level between 10x and 40x to be selected. For example, with a Stereo Zoom Microscope, you could theoretically use a magnification of 32x.

Stereo Zoom Microscopes are designed for serious scientists and microscopists.

Digital Microscopes

Digital Stereo Microscopes combine a Traditional Stereo Microscope with a Digital Camera to view images through a screen, as opposed to an eyepiece. Many digital microscopes also feature digital zoom to achieve a higher magnification than standard stereo microscopes.

However, substituting physical eyepieces for a two-dimensional flat screen means that you lose some depth perception that is required for the clear examination of a three-dimensional subject. The extent to which this is noticed is reliant on the quality of the display.

Digital Microscopes are used for teaching, demonstrations and for passionate scientists wanting a more ergonomic way to observe 3D objects.

Figure 2 shows the Saxon 9-Inch LCD Digital Stereo Microscope.

Types and Uses of a Stereo Microscope: Image of a Digital Stereo Microscope
Figure 2. Saxon 9-Inch LCD Digital Stereo Microscope

Digital Microscope Cameras

You could also choose whether to view samples through the eyepieces or through a digital camera. External Digital Microscope Cameras are slotted into an eyepiece tube to deliver much the same functionality as an integrated digital microscope. When using an external digital microscope camera, microscopes with a trinocular head are advantageous as they allow you to retain the binocular eyepieces and attach the camera to the top of the microscope. However, you cannot use both the eyepieces and a digital camera at the same time.

Digital Microscope Cameras are essential for scientists wanting the depth-of-field that eyepieces offer as well as the ease of use of a digital screen.

The Saxon 3 Megapixel Digital Microscope Camera is shown below, attached to a microscope with a trinocular head.

Types and Uses of a Stereo Microscope: Image of a Digital Microscope Camera
Figure 3. Saxon 3 Megapixel Digital Microscope Camera

Handheld Microscopes

Conversely, Handheld Digital Microscopes do not use a conventional microscope design and are more portable and versatile than traditional microscopes. But with such a minimal design, these types of microscopes are often not as sturdy as traditional microscopes and have a shallower depth of field. However, they are also generally more affordable than conventional microscopes.

These microscopes are intended for professional use and jobs such as industrial quality control and component inspection. However, with such a user-friendly design, these microscopes are also great for children and other beginners.

The Celestron Handheld Digital USB Microscope Pro is shown below.

Types and Uses of a Stereo Microscope: Image of a Celestron Handheld Digital Microscope USB Pro
Figure 4. Celestron Handheld Digital USB Microscope Pro

Mounting Your Phone to a Microscope

Using a phone to capture stills and recordings of samples is an alternative that is both simpler and more affordable than the options above. The Saxon ScopePix Smartphone Adapter 2s attaches directly to the eyepiece of a microscope, allowing you to take stills and recordings using your phone camera. The ScopePix 2s is also compatible with most telescopes.

Smartphone Adapters are useful for individuals looking for an inexpensive entry into microphotography.

Gemological Microscopes

Gemological Microscopes (or Gemology Microscopes) are specially designed stereo microscopes used by gemologists for the examination of precious jewels, gems and stones. Generally, these microscopes feature jewel clamps or gem tweezers, which are very similar to stage clips, except they protrude upwards. These jewel clamps are used to examine gems when elevated to create a truly three-dimensional image.

Gemology Microscopes allow for observation of gems under darkfield illumination with the use of a Dark Field Condenser. A Dark Field Condenser creates a hollow cone of light to allow only angled, oblique light to pass through a stone, preventing direct light from entering the objectives (Bagnell, 2012). This allows for any imperfections in gems to be clearly illuminated for observation through the eyepieces.

Gemological Microscopes are an essential device for professional gemologists and hobbyists studying the authenticity and quality of gems and stones.

The Saxon GSM 10x-160x Gemological Microscope is illustrated below.

Types and Uses of a Stereo Microscope: Image of a Saxon GSM Gemological Microscope 10x-160x
Figure 5. Saxon GSM Gemological Microscope 10x-160x

Boom Stand Stereo Microscopes

Boom Stand Stereo Microscopes use an unconventional design to offer greater working room. The use of an adjustable arm also means that the microscope head is a lot more versatile than a standard stereo microscope. These microscopes are often not illuminated and are instead generally adaptable with ring lighting.

Boom Stand Microscopes are ideal for industrial users needing versatility and significant working distance for applications of larger objects such as circuit boards, soldering, engraving and watchmaking and repair.

The Saxon Biosecurity Inspection Microscope 7x-45x is a popular boom stand microscope.

Types and Uses of a Stereo Microscope: Image of a Boom Stand Microscope
Figure 6. Saxon Biosecurity Inspection Microscope 7x-45x

LED Magnifying Lamps

LED Magnifying Lamps feature a low, fixed magnification below 10x. They are easy-to-use, versatile and lack the magnification power and the functionality of a full-sized Stereo Microscope.

They are suitable for embroidery, reading, general examination and circuit board and electrical work, where a wide field of view is essential. LED Magnifying Lamps are also useful day-to-day microscopes for the vision impaired.

The Saxon 7.5-inch LED Desktop Lamp Magnifier MX170 is shown below.

Types and Uses of a Stereo Microscope: Image of a Saxon LED Lamp Magnifier Desktop MX170
Figure 7. Saxon LED Lamp Magnifier Desktop MX170

What Can You Observe With A Stereo Microscope?

Below, I have imaged some samples to demonstrate the different types and uses of a stereo microscope, using an Apple iPhone 11 mounted to a Saxon ScopePix Smartphone Adapter 2s.

Boom Stand Stereo Microscope

The image below displays the impressive depth-of-field of a Saxon Biosecurity Inspection Microscope 7x-45x Boom Stand Stereo Microscope.

Stereo Zoom Microscope

Below I have imaged an American Quarter Dollar at different magnifications under a Saxon RST Researcher Stereo Zoom Microscope 10x-40x.

Gemological Microscope

Here, I have used a Saxon GSM 10x-160x Gemological Microscope to observe a rock from the Ores sample.

How Are Stereo Microscopes Different to Biological Microscopes?

Unlike Stereo Microscopes, Biological Microscopes (or Compound Microscopes) are used to view microscopic samples of specimens on slides. Biological Microscopes magnify at high power so are better for the observation of microscopic plant and animal cell samples. For example, you could observe samples of onion cells, liver cells, kidney cells or even a bone marrow smear.

The easiest way to distinguish between the two types is by the fixture of the stage. Stereo microscopes feature a stage plate fixed to the base of the microscope, whereas biological microscopes have an adjustable stage.

Could a Stereo Microscope be the Right Microscope for You?

There are evidently several Different Types and Uses of a Stereo Microscope. For a microscope that delivers extraordinary, three-dimensional views of larger objects and specimens, a Stereo Microscope may be most suitable for you. If you are after a microscope to observe truly microscopic details of samples in great detail, a Biological Microscope may be a more suitable choice.

If you are still unsure about which choice to make, we also have a beginner’s guide to microscopy on our website.

Whichever you choose, we hope you learn to love the endless possibilities of your microscope.

REFERENCES

Abramowitz, M. & Davidson, M. W. (n.d.). Darkfield Illumination. EVIDENT Olympus. https://www.olympus-lifescience.com/en/microscope-resource/primer/techniques/darkfield/

Bagnell, J. C. R. (2012). Chapter 9 Dark Field Microscopy. University of California, Irvine. https://www.chem.uci.edu/~dmitryf/manuals/Fundamentals/Dark%20Field%20microscopy.pdf

Chambers, W., Fellers, T. J. & Davidson, M. W. (n.d.). Darkfield Illumination. Nikon Microscopy U. https://www.microscopyu.com/techniques/stereomicroscopy/darkfield-illumination

MRC Laboratory of Molecular Biology. (n.d.). Microscopes. https://www2.mrc-lmb.cam.ac.uk/microscopes4schools/microscopes1.php

Nothnagle, P. E. (n.d.) Introduction to Stereomicroscopy. Nikon Microscopy U. https://www.microscopyu.com/techniques/stereomicroscopy/introduction-to-stereomicroscopy

saxon. (n.d.). saxon Biosecurity Inspection Microscope 7x-45x [Online image]. https://www.saxon.com.au/media/catalog/product/cache/e744b0a71cb9bdd2eb52eff7374ce483/s/a/saxon_biosecurity_inspection_microscope_7x-45x.jpg

saxon. (n.d.). saxon RBT Researcher Biological Microscope 40x-1600x (NM11-4100II) [Online image]. https://www.saxon.com.au/media/catalog/product/cache/e744b0a71cb9bdd2eb52eff7374ce483/s/a/saxon_rbt_researcher_biological_microscope_nm11-4100ii_-_sku_311009_1.jpg

saxon. (n.d.). saxon 3 Megapixel Digital Microscope Camera [Online image]. https://www.saxon.com.au/media/catalog/product/cache/e744b0a71cb9bdd2eb52eff7374ce483/s/a/saxon_3_megapixel_digital_microscope_camera_1.jpg

saxon. (n.d.). saxon 9” LCD Digital Stereo Microscope 11x-457x [Online image]. https://www.saxon.com.au/media/catalog/product/cache/e744b0a71cb9bdd2eb52eff7374ce483/s/d/sdm_digital_microscope_4_.jpg

Zeiss. (n.d.). Magnification and Lateral Magnification. https://www.zeiss.com/microscopy/int/service-support/glossary/magnification-and-lateral-magnification.html

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