If we ask you what the difference between digital and optical microscopy (or stereo microscopy) is, you’ll probably say that there’s no eyepiece on a digital microscope. And you’d be right.
On digital microscopes, you use a monitor to display a sample instead of looking through an eyepiece.
There’s several reasons for that:
- You don’t have to bend your neck to look through the eyepiece
For many microscope operators, looking through an eyepiece causes work related pains and you can eliminate those by creating an ergonomically correct setup
- It’s easy to document your work
In general, it helps to see a digital microscope like a computer. By displaying everything on a monitor, you can use the equivalent to a “Print screen” button on your microscope control box to easily capture a photo of your work. It’s a bit more complicated than that on a traditional stereo microscope
- You can use apps
Okay, it’s not the monitor per se that allows operators to use apps in their inspection processes. But if we continue the computer comparison from before, the monitor can display the many capabilities of the digital microscope, including apps, in a way that’s just not possible on a stereo or optical microscope
- It fosters collaboration between colleagues
With a monitor, everyone can look at a sample simultaneously. There’s no need for taking turns at looking through the eye piece and trying to explain to the person currently using the microscope where to look by pointing with a pen, finger or something similar. On a digital microscope, you’re looking at the sample at the same time, making not only training of new employees easier but asking a colleague for a second opinion is also made easy
But there’s more to it than that. Using a monitor also affects the Magnification and Field of view of the microscope.
Let’s start with Field of view of a microscope.
What is Field of view of a microscope?
Field of view, sometimes abbreviated to FOV, refers to how much you are able to see when using an inspection microscope. With a digital microscope, Field of view will be bigger than on a optical microscope even if both microscopes are at the same magnification level. This means that you’ll be able to see more of a sample om a digital microscope than on an optical microscope.
The main reason for this being the 16:9 widescreen camera aspect ratio of the monitor that’s being used with a digital microscope.
See the difference yourself with a ruler
It’s quite easy to see this difference in Field of view:
- Start by adjusting an optical microscope and a digital microscope to the same magnification level
- Place a metric ruler underneath each microscope
It will quickly become apparent that despite using the same magnification level on both microscopes, you have a higher Field of view on the digital equipment, allowing you to see more your sample.
Magnification levels on a digital vs. optical microscope
We now know that when using the same magnification levels on a digital and an optical microscope, you will have a bigger Field of view on the digital microscope.
But what happens if we adjust the microscopes to have the same level of Field of view then? Well, in order to achieve the same Field of view on the optical microscope, we need to zoom out which will prevent us from seeing the same level of detail on our sample as magnification refers to the number of times a sample if reproduced: By lowering the magnification, we’re lowering the number of times the sample is reproduced.
In this case, this means that our sample is reproduced a higher number of times on the digital microscope, allowing us to see more details at the same field of view.
With this in mind, Field of view of a microscope and Magnification are two interlocked factors related to microscopy – regardless of the type of microscope we’re talking about. But because of the 16:9 widescreen camera aspect ratio of the monitor used with digital microscopes, you will either experience:
- Higher magnification on a digital microscope at the same Field of view compared to an optical microscope
- Bigger Field of view on a digital microscope at the same magnification level compared to an optical microscope
Want to learn more about digital microscopy?
Here’s a selection of blogposts for you to read next.