A stereoscopic microscope, also known as a dissecting microscope is an optical device that is used to observe and study small three-dimensional objects.
But, as the name suggests, these microscopes are also used to dissect small specimens like plants, insects, or other biological organisms.
This device has a relatively low magnification which can change between two and a hundred times, but this will depend on what microscope you are using.

The main feature that sets a stereo microscope apart from the rest is the fact that these devices will usually have two different and separate paths. Both of these light paths will have two different angles you can view the specimen.
This feature allows you to study and observe three-dimensional specimens and items with ease. For this reason, this type of microscope is well suited to taking a closer look at target species and dissecting them.
On top of that, the stereo microscope is also well suited to fixing circuit boards and other small pieces of technology that are too small and finicky to deal with using just your eyes.
But what exactly do all the parts of a stereoscopic or dissecting microscope do? Find out everything you need to know about the parts and functions of these amazing devices.
What Are The Basic Parts Of A Stereoscopic Microscope?
Microscopes are quite complicated devices and there are a ton of parts that make up these amazing devices.
In short, a stereo microscope has Three basic parts and each of these contains several smaller components that make up the whole microscope. Below are the three main parts and some of the things that they have in each section:
- Head – The head is the part that you usually look through and contains all the lenses and eyepieces. This part of the microscope will casually have eye cups, 10x ocular eyepieces, a trinocular port, and an objective lens.
- Arm – The arm is the section between the head and the base. This part of the microscope usually has a focus control, upper illumination, focus arm, and zoom control.
- Base – The base of the microscope is exactly what it sounds like, it is the part of the device that will be in contact with the surface you place the microscope on. This part usually contains stage clips, a stage plate, an on and off switch, the incident or top illumination control, and finally, the transmitted or lower illumination control.
Of course, what you see on each stereoscopic microscope may differ slightly depending on the model you have. But in general, these products will have a bare minimum of the following.
Okay, now that we have an idea of what a stereo microscope is made up of we can finally go into each part and explore its function in more detail. So, without further ado, let us get started!
Let’s Take A Closer Look At The Head
The head of the microscope is sometimes referred to as the body, but this is only because all the important things that make a microscope work are actually located in this part.
This part will usually contain the optical parts of a microscope or the lenses that are used to see the samples you are looking at.
On top of having the optical parts, the head will also have a few parts that move.it is because of these movable parts that you should always avoid holding or carrying a microscope by the head as you can easily damage the delicate components.
Let us take a closer look at the components that you will find in the head of a microscope:
The Eyepieces
The eyepiece is also known as the ocular lens. This part of the head is an optical component and is the part that comes close to the human eye when we try to example something under the microscope.
This part of the microscope can also be found in compound microscopes but despite this similarity, the parts are so different that an eyepiece from a stereo microscope cannot be used in a compound microscope and this is down to the fact that the diameter of the eyepiece is too different to be compatible.
The eyepiece is the part of the microscope that magnifies the image that we see. In short, the eyepiece will make the image that you see bigger which allows scientists to view the specimen in more detail.
If you were to view something through the eyepiece you should make sure that your eye stays about ten to fifteen millimeters away from the eyepiece. This is so that you can get the full field of view.
This distance is referred to as eye relief and is super important as this distance can help assure that eyelashes do not get in the way of what you are trying to observe.
If you wear glasses you may need to make sure that you stand even further away from the eyepiece. Between twenty-five and thirty millimeters, away should be enough eye relief to give you a clear and unobstructed view.
You may notice that different stereoscopic microscopes have different eyepieces and this will depend on the type of microscope you are using.
Some eyepieces that you encounter will have more than one lens in a single eyepiece and this is known as a lens doublet, lens triplet, or field lens doublet and this will depend on how many lenses your eyepiece has inside it.
Microscopes with so many lenses are quite complicated. But if you have a stereo microscope with an eyepiece that has just the eye lens and the field lens you will be able to examine your samples just fine.
Typically, the eyepiece your microscope has will have documentation that details the specification, magnification, and other features your device has.
Your stereo microscope, for example, may have a magnification of ten and with this information, you can expect to see your specimen or sample ten times more closely than the naked eye.
Aside from the magnification, you may notice that your eyepiece has ‘WF’ written on it somewhere. These markings indicate that your eyepiece has a wide field of view.
In short, this just means that when you are observing something you will be able to see more in a wider area. The most common field of view that you can expect to see in a stereo microscope is either eighteen millimeters or twenty millimeters.
Neither of these fields of view will increase the magnification or resolution that you will see. All that this means is that your field of view will be wider.
The eyepiece will have a diopter adjustment knob that will let you adjust separate eyepieces which will help you if you have a different vision in different eyes.
On top of that, you should have the ability to change the interpupillary distance for your eyepieces. This will allow you to change the distance of the eyepieces and move them closer or further apart to suit how close or wide apart your eyes are.
Depending on your microscope you may have more adjustments that you can make. So make sure that you understand your microscope and what you need it to do.
The Objective Lenses

This part of a stereoscopic microscope is absolutely essential. This is the lens that will magnify whatever you are looking at. It is also designed to bring together the light that hits it so that it can make the picture that you see on the ocular lenses.
Similar to ocular lenses the objective lens is made from glass which is the best material that they can be made of. The cheaper stereo microscopes often have their lenses made out of plastic.
In compound microscopes, the objective is attached to the nosepiece and can be identified individually. In a stereo microscope, the objective lens is normally found in a cylindrical cone and will not be seen directly.
This cone can be turned or moved in order to change the magnification that you are seeing.
On top of that, there is usually an objective lens for each eyepiece and this is how you get that fantastic three-dimensional image that these microscopes are known for.
The Barlow Lenses
On top of having an objective lens for each eyepiece, many stereo microscopes also come with an accessory known as a Barlow lens.
This lens is an auxiliary lens that is used to decrease or increase the total magnification as a factor that it has been given.
For example, with a Barlow lens that has a magnification power of times two, you will notice that the overall magnification will increase by this amount.
As that number changes the magnification will also change by that amount. This is a super easy accessory that you can install on your stereo microscope with little hassle.
The Adjustment Knobs
There are several adjustment knobs located on the head of the microscope. In this section, we are going to take a closer look at what these knobs are and what they will do:
- Zoom Knob – As the name indicates, the zoom knob allows you to zoom in and out without moving the head of the microscope. These knobs are generally located just under the eyepieces. With these knobs, you can zoom in to an area to get an even closer look at it. You will need to use the zoom knob in tandem with the focus knob to get a clear image of wherever you are studying under the microscope.
- Focus Knob – As the name suggests this knob will allow you to focus the lenses. This device is also known as the course knob and is often located on the arm or the head of the microscope. But this will depend on the type and make of your device. When you turn the knob the microscope head will be raised or lowered which will make the working distance larger or smaller. When you slowly turn this knob you can bring your subject into focus.
Let’s Take A Closer Look At The Arm
The arm is very important in the construction of a microscope. It is actually referred to as the backbone of any microscope and this is because they support the head and connect the whole device to the base.
Some of these arms or stands are hollow, but others will have a cylindrical rod in the center. This is known as a rigid arm and this type of arm will be more shaped like a cube than those that are hollow.
The arm is also the house for the power cord which is used for powering the microscope and giving you the illumination you need.
The power cable is often housed in the arm or at the very least it will originate from the uppermost point of the arm.
The reason for this pavement is so that whatever you are looking at will have a light shone from adobe which will in turn allow you a more clear viewing experience.
On top of having a power cord located in the arm, there could also be an arm track that will help your microscope head to move up or down and even allow you to adjust the focus.
But this feature is more common in stereo microscopes that have a rigid arm.
Okay, let’s go over the main functions of the arm of a microscope before we move on to the next section:
- Safely Lifting or Carrying the Microscope – If you have ever been taught how to carry or hold a microscope you will know that you are always told to carry it pt hold it by the arm or the base as this is the most sturdy and durable part of the whole machine and will be the least likely method of carrying to result in damage to your stereo microscope.
- Houses the Power Cord – As we have said before, the arm is usually the house of the power cord. This cord will power the microscope and give the power to the lights that allow you to see whatever you are looking at more clearly and in good light.
- Houses the Focus Knob – The arm usually is where you will find the focus knob on a microscope. This knob will allow you to focus on the image you are seeing and there may even be other knobs that will allow you to move the head up and down.
- Supports the Head – As we said before, the arm is also known as the backbone of the microscope because it connects to the base and the head. As a result, the arm plays a huge role in supporting the head and allowing it to move up and down as needed.
Let’s Take A Closer Look At The Base
The base of a microscope is one of the most important parts of the whole machine. After all, without a good sturdy foundation, nothing would work.
As the name implies this is the part of the microscope that supports everything else and keeps everything grounded on a base.
This part is usually wide and quite heavy in order to make sure that the microscope remains stable while in use on a table or other work surface.
Depending on what model of microscope you get the base may be larger or smaller than others. But this does not detract from the importance of this part of a microscope.
Okay, let’s go over the main functions of the base of a microscope before we move on to the next section:
- Support the Rest of the Microscope – The main function of a microscope is to be the heaviest part of the microscope in order to provide support and stability for the whole device.
- Can be a Part of the Stage – The stage is the part of a microscope that is used to place a specimen or object to be viewed. In compound microscopes, the stage and the base are different parts and separate from each other. But in stereoscopic microscopes, the base often acts as the stage as well. Depending on the model of microscope you get, your stereo microscope may come with a pair of clips that are used to hold the slide or specimen in place while you study, dissect or view it. These clips are oftentimes right at the base of the stage and will be directly below the objectives or lenses.
- Safely Lifting or Carrying the Microscope – As we have mentioned before, the arm or the base is used as a safe anchor that you can use to lift or carry a microscope without the risk of breaking the more delicate parts of the microscope.
A Closer Look At The Stage And What It Is Used For
As we said before, the stage is the area that will hold a slide or organism so that you can view or study it. Stages are not always a part of the base, but in the case of Stereoscopic microscopes, they typically are.
So, let us take a look at what exactly a stage will have attached to it.
- Lighting and Lighting Control – The stage is usually where you will find the light controls, adjustment knobs, and light intensity regulator. The type or model of your microscope will dictate whether you will have all of these adjustment options or just a single overhead stage light or more light sources. If you have a microscope that has stage lighting and overhead lighting you will almost likely have two knobs that will adjust each one independently. They are often opposite each other and will be on the arm or the base depending on the microscope.
- On and Off Switch – The stage is often where you will see the on and off switch. But it can also be found on the base of the microscope. The on-off switch will turn the illuminator on or off. It is essential that you remember to lower the light intensity before you switch the microscope off as a sudden bright light turning on can cause the bulb to become damaged or break.
Important Hidden Components

We have taken a look at the most prominent components of a microscope. But there are some hidden parts that play a huge role in making a Stereo microscope work as it does.
In this section, we are going to take a closer look at some of these important components that you never get to see. So, without further ado, let us dive right in!
- The Relay Lens – The relay lens is responsible for reverting the image that you see and is an additional part of the imaging system that makes up a microscope.
- The Reticle – This small yet very important part of a microscope is a small piece of glass that has a grid on it and is used to accurately measure whatever you are studying under the microscope.
- The Prism – The prism is responsible for bending the light that enters the lens. When this happens the orientation of the image changes as a result.
How Do You Use A Stereo Microscope?
You will know by now that a stereoscopic microscope has less power than other types of microscope and its main purpose is to allow you to study larger specimens like stones, insects, or plant parts.
Stereo microscopes can be used in several different ways and in this section. The way that you use this device will depend entirely on what you are studying.
So, in this section, we intend to take a closer look at how exactly you use these amazing microscopes.
But before we can get into the step-by-step guide we need to go over the two main stages that you will encounter depending on the make or model of your stereo microscope.
- Stage Type One – The first type of stage is normally used when you are looking at samples or specimens that are not transparent and will stand out best on an opaque background. These stages are most often black or white.
- Stage Type Two – The second type of stage is typically used when you are observing a sample or specimen that has been mounted on a slide. These stages are normally clear or frosted glass so that the stage lights can illuminate whatever you are examining.
Now that we have an idea of what kinds of stages you can expect to see on a stereoscopic microscope let us get into how you use this type of microscope.
Step 1 – The first thing you need to do is make sure that you have the right stage installed in the microscope. This will happen before you turn the unit on.
If you notice that there is a stage already installed and it is not the right one then all you need to do is loosen the stage plate lock screw and take the old stage off before putting in the correct one.
If the stage you are putting in is glass or frosted it is generally installed along with a blue filter which will be placed at the center of the base. This will happen before you put the glass stage on the microscope.
When you have placed your stage make sure that you have tightened the locking screw so that everything is secure.
Note: Before you turn the light on you will need to make sure that the intensity has been turned all the way down. This will help your bulb last longer and lower the risk of the bulb blowing.
Step 2 – Now that you have your stage in place and secure you can finally turn on the microscope. This switch can usually be found on the side of the base of your stereo microscope.
Once the device has been turned on you can then turn on the transmitted illumination or the incident illumination. Which one you have will depend on the make or model of your microscope.
Some have one or the other while other microscopes will have both of these illumination components.
Step 3 – Now that the device has been turned on you can finally lower the head to a point that suits the sample you are studying. You can do this by turning the coarse focus knob.
If you slowly lower the head as low as it can go you will have a great starting point and can make smaller adjustments depending on what you are intending to observe.
Step 4 – next, you will need to adjust the eyepieces so that they work best for your eye strength and distance apart. So, start by looking through the eyepiece and very gently adjust the distance by pulling or pushing them closer or further apart.
The aim of this is to make sure that you have one field of view that is in focus.
If you do not have a sample mounted on the stage yet you should aim to have a single circle visible when you look through the eyepiece. If the interpupillary distance is incorrect you will see two circles, so make sure to adjust until there is only one circle or field of view in focus.
Step 5 – Now that you have the preliminary prep work done you can mount your sample or specimen and start focusing on it using the right knobs.
You will need to decide whether you are going to have the illumination turned on and suitable for whatever you are studying.
Your item should be in the middle of the stage before you focus. Once you have your specimen placed you can use the focus knobs to bring the object into focus and make the image you see nice and clear.
With the microscope head all the way down as we said to do in step three you can now move it up and down until the image you see through the eyepiece is crystal clear and in focus.
Step 6 – With the image in focus, you can finally zoom into the item you are observing. There should be zoom knobs on your stereo microscope that will allow you to see your sample up close and personal.
One thing to note when you are using the zoom knob is that when you are using it your image may become blurry or distorted. For this reason, you should use it in tandem with the focus knob to get the best results.
We recommend that you also adjust the light intensity so that you can get better contrast and thus see your object better.
Note: Once you have finished studying your specimen or sample you should always make sure that you have set the zoom back to the lowest setting and the light intensity is also at the lowest setting before you turn the microscope off.
This will ensure that your microscope will last longer and that components will not malfunction the next time you decide to use the device.
Final Thoughts
We hope that you have enjoyed reading this article on how stereoscopic or dissecting microscopes work. WE hope that we have been able to cover everything you need to know about these amazing devices.
Have a fantastic day and have fun observing your specimen with your new stereo microscope!
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