How to Focus a Microscope on High Power

By Contributing Writer

Microscopes are very expensive tools used by science to examine objects that are too small to be seen with the naked eye. These tools are very useful, and can provide valuable information to the user, but will only work if they are used properly. If improper use occurs, it could damage your microscope and your slides. Getting the objects into focus can be tricky, therefore quite frustrating. Learn how to focus a microscope.

Step 1

Plug in your microscope and remove the cover. If there is a lens cover, remove it and set it aside. Make sure all your slides and lenses are clean. Check the light and make sure nothing is obscuring it that will throw shadows on your specimen.

Step 2

Position the slide underneath the lens. See that your specimen is placed under the center of the lens. Make sure the lens is set to low power before you turn it on.

Step 3

Focus on your specimen using first the course knob, the bigger of the two. This is to get a general picture of your specimen. Now you are ready to turn the fine focus knob, until you can see the specimen clearly. Do not move on to Step 4 unless your object is in focus. Focusing on your specimen first under low power is the best way to focus a microscope.

Step 4

Center your specimen underneath the lens and switch to high power. Proceed slowly to avoid damage to the lens, slide or specimen. Hold the side of the slide when you switch to high power to ensure that it stays in place.

Step 5

Re-focus, using only the fine focus knob to adjust while the microscope is on high power. If you use the course knob, you are likely to overcompensate on the distance, and crack your slide. Turn the fine focus knob only slightly in either direction to focus on the specimen under high power.