Posted by Fred Koenig on Nov 20th 2020

Microscope Magnification - Pushing The Limits

How Much Can You See Through a Microscope?

What you will be able to see under a high-power microscope depends somewhat on how well you use it. For basic viewing, of course, anyone who can see, will see more through a microscope – but there are ways to increase your skill at focusing in on very small objects and surfaces, making it more likely you’ll be able to see structures and features at even the smallest sizes a microscope can display.

The best way to begin is to always start with your least powerful objective (usually the 10x). This is also the longest of them, which is good, because it ensures that you won’t absentmindedly rotate from a shorter objective to a longer one when there isn’t sufficient working distance to do so, resulting in a crash between the lens and the sample of cover slip.

Before changing to a higher-powered objective, focus on your sample at 10x, and carefully center it in the field of view. Then you should be able to increase your magnification by rotating to a higher-powered objective. The specimen should be almost in focus, needing only fine focus adjustments to sharpen the image. Once you have focused and centered under the second objective, repeat the process for the third and, if your microscope has one, the fourth objective.

Once you reach about 400x magnification, you will be able to see structures such as blood cells, bacteria, and protozoans. If your light does not get too hot (which can cause their deaths), you can see these little creatures swimming around, consuming food, etc. Once you increase magnification to 1000x, you will be able to examine organelles and other features of these tiny objects and creatures.

Each time you increase magnification, you are looking at a smaller amount of area through your microscope; this (usually circular) area is called the “field of view.” Some specimens will fit inside a given field of view, others will not. Depending on how much of your sample you need to see at a time, you will need to decide between higher magnification with a smaller field of view or viewing more of the object at a lower magnification. In many cases, you might want to do both and combine your findings.

Here is a list of fields of view at various magnification levels.

  • Field of view at 40x magnification is approximately 5mm.
  • Field of view at 100x magnification is approximately 2mm.
  • Field of view at 400x magnification is approximately 0.45mm, or 450 microns.
  • Field of view at 1000x magnification is approximately 0.180mm, or 180 microns.

You can also learn about the field of view of a microscope here.

We have lots of other guides on microscopes, including:

If you want to buy a new microscope, then you can shop different types on our website at the links below: