Although you might think there’s only one type of microscope out there, you’d be mistaken.
And whilst the typical compound microscope you’ll see in schools is undoubtedly the most common, there are a ton of different variations of microscope. They have magnifications of 10x all the way up to 1,000,000x depending on their power, and they can utilize light or electrons depending on what method is used.
So depending on what the need is, a different type of microscope is going to be an advantage to each different need. Here’s a few of the different types of microscopes that you’ll find in various different
Types of Microscope
So, let’s take a look at some of the most common types of microscope around, starting with the most common and working our way through to some less common microscopes that you may not have heard of.
We’ll start with compound microscopes, because nowadays, these are the most common type of microscope that you’re going to find. There an advancement on older microscopes, and they’re much better nowadays than they have been in the past.
The way a compound microscope works is by using two lenses. So, we have the first lens that’s attached to the microscope itself – be this 10x, 40x or 100x. Then, we have the opportunity to add to this with another lens, which is usually 10x or 25x in the majority of microscope sets. So with these added magnifications, we’ll get a much higher magnification than is possible with just 1 lens (e.g. 100x lens + 25x lens = 2500x magnification!). This kind of high level magnification is necessary for viewing things like cell structure.
In the past, we used what we refer to now as a ‘simple microscope’ for scientific uses. Nowadays, they’re really only used for inspecting jewellery and other magnification purposes. The main difference between a simple microscope and a compound microscope is the amount of lenses that they use.
A simple microscope is basically a really, really powerful magnifying glass – it works in exactly the same way, by using only one lens. Although this might sound kind a basic (and it is!), this could reach 100s of x of magnification, and was used as the primary way to view subjects for a long time.
Although simple microscopes have their place in history, there simply isn’t much demand for them anymore due to the increasingly popularity of multi lens microscopes.
A stereo microscope will usually operate at a much lower magnification in comparison to other microscopes. Instead of the 2000 and 3000x magnifications you’ll see with compound microscopes, you’re more like to use a stereo microscope at 100 or 200x.
Stereo microscopes are better used for solid surface, three dimensional subjects – things like insects are perfect to be used with stereo microscopes. This is because of the way that the microscopes are designed, and the way that they perceive an image. With a compound microscope for example, the light will transmit directly through a slide and whatever is on it, be it bacteria or whatever else. This gives you an illuminated view of the subject, which is great.
But if you’ve ever tried to use a thick, 3D object in a compound microscope, then you’ll realise that it doesn’t work well. Why? Well, because light cannot pass through, that’s why! With a stereo microscope, this isn’t a problem, because they’re not design to view light through transmitted light. Instead, they work by using reflected light, which allows the viewing of 3d subjects. So, for opaque matter, a stereo microscope is the way forward.
Created as more of a novelty than anything else, USB microscopes have become more and more popular in recent years. They come in especially useful for students and junior engineers who might not have the cahs to splash out on a more expensive microscope, and they can easily make do with a USB microscope for the time being.
In the same breath, they are fun! You’re going to get a surprising amount of magnification at a really low price, and if you’re looking for something to have fun with the kids with, then it might be worth getting a USB microscope first. Although the cheaper ones can break easily within a short amount of time, there are a few good USB microscopes out there you might want to consider.
USB microscopes are just low powered digital microscopes – I’ve seen them referred to as ‘glorified webcams’, which is true in a way. But in my opinion, they’re much more useful and they’re an ideal way to get started with microscopes, especially for kids. A lot of the cheap USB microscopes will say they’re 1000x multiplication – bear in mind this is pretty much nonsense. They’re usually around 50x magnification, which is enough to have some fun with.
Although USB microscopes tend to be associated with cheap fun, there are some more expensive ones out there too which do a better job. So, higher end USB microscopes do exist, as long as you’re willing to do some research to find them!
Digital microscopes are essentially your average microscope, except with the addition of an in built LED light source. This allows the optical view of the microscope the ability to record and take photos of the image. Although you might associate digital microscopes with the cheap ones you find on Amazon, they are used in professional circles too.
The good thing about a digital microscope is that you don’t necessarily need to use an eyepiece. You can easily monitor where the focal point of the microscope is on the LCD screen, which provides an alternative viewing method. This is great for obtaining quick results, which is ideal for viewing a lot of subjects within a short frame of time. Of course, with a digital microscope you’ll need to be connected to a power source, which can potentially be a drawback.
Scanning Electron Microscope
Not all microscopes use light to form an image. The Scanning Electron Microscope, referred to as a SEM, uses electrons as opposed to light illumination. It works by coating the subject in gold, and the electrons bouncing back off of the 3D object to form an image.
If you’re looking for an in depth explanation of scanning electron microscopy, this is the best video on YouTube that talks about the topic. Although the video is a bit goofy, there’s a lot of good information and it shows the entire process of SEM.
Transmission Electron Microscope
Whereas scanning electron microscopes work for 3D images, transmission electron microscopes are used for 2D subjects. Transmission Electron Microscopes, or TEMs, work in a very similar way to projectors. Instead of transmitting light through the 2D subject, they instead transmit electrons to portray an image. This kind of equipment is extremely expensive, and like SEMs, they can get insane levels of magnification too.
Confocal microscopes were introduced in the late 1950s as an alternative to fluorescent microscopy. As the sound indicates, fluorescent microscopes use an intense amount of light evenly distributed – this high amount of light can cause photo bleaching and an altered image.
Now, a confocal microscope isn’t that much different from a fluorescent microscope. But, there are a few modifications that have been made to make a difference. Instead of using a regular mercury lamp, confocal microscopes rely on lasers instead as a source of light. They also use a CCD detector to take images through a pinhole, as opposed to a typical photodetector.
Generally, confocal microscopes are used in extensive scientific areas like cell biology, but also in other areas where 3D images are necessary.
Overall, these are just some of the different types of microscopes that you’ll find being used, both in a professional and non professional manner. Whilst you might only need a simple microscope for some things, as technology has advanced over the tears we now have the possibility to get insane amounts of magnification, which is entirely necessary for analysing biological cells amongst other things.