Explaining Field of view for microscopes

When talking microscopy, you’ll often run into the term Field of view. In this blogpost, we’ll explain what Field of view means, why it’s important and why it looks different on a digital microscope compared to traditional microscopes.

• What does field of view for microscopes refer to?
• Why is it relevant to talk about field of view for microscopes?
• The differences in field of view for microscopes
• Field of view for TAGARNO’s digital microscopes

What does field of view for microscopes refer to?

Field of view, also abbreviated FOV, refers to how much you’re able to see of a magnified sample at a specific magnification level and is displayed in distance units. Field of view can thus be used to determine the approximate size of an object that is too small to measure manually. If you’re analyzing samples, field of view can also be used to count and calculate percentages, fractions, areas or size of particles in the sample. More on that later.

Field of view will vary depending on the lens and magnification level, you’re using. The higher magnification you’re using, the smaller the microscope field of view will be. Have a look at the images below.

The two photos are of the same PCB, but at different magnification levels. The first photo is taken at around 5x magnification, the latter at around 40x magnification.

The photos clearly shows that the field of view is reduced as we’re increasing the magnification level. While this allows us to see less of the entire sample, increasing the magnification and thereby reducing the field of view enable us to see our sample in greater detail.

Why is it relevant to talk about field of view for microscopes?

Field of view is used to determine the actual size of the magnified area and can therefore be used to indicate the real-life size of something. For an accurate representation of an object’s real-life size, we recommend using an app like Measurement app that allows you to measure the object itself and not just the field of view.

Field of view for microscopes becomes even more important if you want to count the occurrence of something in a sample.

Let’s use a sample of durum wheat, also known as semolina, as an example. During the quality control process of semolina, millers must count the number of visible specks or impurities in the flour because specks in semolina cause brown or dark flecks in pasta and thus have a negative impact on the value of the semolina.

During their quality control process, the miller will therefore prepare a sample of the semolina and count the number of specks in it, either manually or automatically with the help of an app like Speck counter. Afterwards, they can divide the number of specks counted with the field of view they were using to report the average number of specks within that field of view. This will tell the miller if their product is of the required quality or if the production needs to be adjusted.

The differences in field of view for microscopes

While field of view is a result of how much magnification you’re using, field of view will also differ depending on which type of microscope you’re using.

Due to the eyepiece of a traditional microscope, whether it’s a compound or stereo microscope, the field of view on a non-digital microscope will always be round.

In comparison, the field of view on a digital microscope will always be rectangular due to the use of a monitor. As a result, the field of view will be bigger on a digital microscope than a traditional microscope, even if you’re using the same magnification on both microscopes.

Field of view for TAGARNO’s digital microscopes

Knowing that field of view can be used to determine the real-life size of an object and count how often something occurs in a sample, a microscope’s maximum and minimum field of view are important factors to consider when choosing your next microscope.

For your convenience, we’ve listed the field of view of the digital microscopes from TAGARNO below.

If you want more details on each microscope, click the button below to review their technical specifications in a side-by-side comparison.