Understand the importance of field of view for microscopes

When talking microscopy, you’ll often run into the term Field of view. This refers to how much of a sample, in inches or metrics, you’re able to see at any given time. Understanding field of view is crucial when it comes to finding the right microscope for your needs and that’s why this blogpost dives deeper into this to topic.

More specifically, in this blogpost, you’ll learn:

• What is field of view on a microscope?
• How field of view helps you find the right microscope
• Field of view on stereo and digital microscopes

What is field of view on a microscope?

Field of view, also abbreviated FOV, refers to how much you’re able to see with your microscope at any given time and is most commonly displayed in either metrics or units.

The field of view will depend on your magnification level. The higher the magnification level, the more you’re zoomed in and the less you’ll be able to see at a time. In other words, the higher the magnification level, the smaller field of view, and vice versa.

Being at a lower magnification level, the monitor on the left-hand side has a larger field of view than the monitor on the right-hand side at a higher magnification level. The larger field of view provides a better overview of the sample while the smaller field of view allows for inspection of more minute components.

A smaller field of view can be useful when examining minute components of a sample or if the sample itself is very small. A larger field of view on the other hand can be used to create an overview of an entire sample or if you’re inspecting bigger samples that don’t require high magnification.

How field of view helps you find the right microscope

When finding your next microscope, it’s important to know how closely you need to inspect your samples in order to find a microscope option that provides the required magnification level and field of view.

As an example, the ZIP from TAGARNO, a Danish manufacturer of digital microscopes, has a field of view 290 mm – 11 mm (or 11.42’’ – 0.41’’). Let’s use a PCBA to illustrate what options this gives us:

Offering a field of view of 290 mm – 11 mm (11.42” – 0.41”), the TAGARNO ZIP is great for larger samples and/or inspections requiring lower magnification.

Thanks to the large field of view, we can use the TAGARNO ZIP to create an overview of our entire sample. When increasing the magnification level and our field of view, we’re able to inspect specific areas of the PCBA more closely. This field of view is especially useful when soldering or reworking faulty PCBAs. However, we’re not able to see the nitty gritty details of the board or components. For this, we need higher magnification and a small field of view.

This is where the TREND comes in. By being compatible with multiple lenses, the TREND offers a larger magnification range and a field of view all the way from 1.60 mm (0.06’’) to 290 mm (11.42’’) depending on your lens of choice.

Offering a field of view of 290 mm – 1.60 mm (11.42” – 0.06”), the TAGARNO TREND can be used for high magnification as well as low magnification tasks.

This means that you can use the same microscope for all your inspections, even if you need to go from a large field of view to a small field of view to inspect the hole or diameter of a via.

Looking at these photos showing the minimum and maximum field of view of the ZIP and TREND respectively, it becomes clear that your choice of microscope will determine how much detail you will be able to see on your sample. For that reason, it’s important that you know which samples you’ll be using the microscope on as well as how large or small details you’ll be inspecting before making your purchase. If you’re looking for a microscope for inspecting very minute details – or if you have a high product mix – choosing a microscope that offers a large as well as a small field of view can make a huge difference in your efficiency. Especially if you save your field of view settings as a preset so the microscope itself can recall your required settings.

Field of view on stereo and digital microscopes

By using monitors in this blogpost to explain and visualize field of view, we’ve been focusing on digital microscopes, a modern take on microscopy that uses cameras and optics to magnify and display a sample on a monitor. This instead of eyepieces typically used on stereo microscopes.

While field of view is a term used for digital microscopes as well as stereo microscopes, there’s an important note to keep in mind. And that relates to the eyepiece itself.

Eyepieces reduces field of view

Due to shape of the eyepiece on stereo microscopes, the field of view will always be round. If you scroll back up, you’ll see that the field of view on the digital microscopes are always rectangular.

While the shape of the field of view may be a matter of personal preference, the shape also affects the size of the field of view. In fact, the field of view on a digital microscope will always be bigger than on a stereo microscope.

Due to its eyepiece, a stereo microscope always provides a round and smaller field of view compared to a digital microscope, even if they are at the same magnification level.

Not only has replacing stereo microscopes with digital microscopes proven to have ergonomic and financial benefits, the field of view on a digital microscope will always be bigger than on a stereo microscope – even if they’re using the same magnification level.

The larger field of view on a digital microscope, even at high magnification levels, allows you to either inspect multiple areas of your sample at the same time or simply provides more context for your inspections. In both cases, the digital display creates a more comfortable setup that helps you perform more efficient and accurate inspections while also being an excellent training and collaboration tool.