Using a Compound Microscope


One of the most common lab equipment is the microscope. As a student, we wander through scientific laboratories in our schools and always find one of these. As we see the microscopes, we cannot help but ask ourselves: “How can I use this microscope?” 

A microscope. It is a great tool that led to great scientific breakthroughs throughout the years, more especially in the field of medicine. However, they started using just the simplest of microscopes, which are single microscopes. A simple microscope usually has one lens that usually plays as a magnifying glass, with relatively high magnification. 

On the other hand, as more advancements are made throughout the years, the scientists eventually came up with a more complex and advanced microscope, the compound microscope. The compound microscope eventually became the most common, as they are the ones that we see inside our school laboratories. These microscopes are more complex because it has a series of lenses made specifically to collect and focus light to transmit through the specimen. It may be more complex and larger than simple microscopes, the compound microscope provides increased magnification and resolution levels and reduces chromatic aberration all at the same time.

A compound microscope is a high-power, high magnification microscope that has a compound and complex lens system. It has multiple lenses, like the objective lenses, which have different magnification levels, and the eyepiece lenses. A compound microscope provides two-dimensional images, while stereo microscopes provide three-dimensional images.

Compound microscopes are specifically used to gain and provide magnification in the range of 40 to 1000 times the size of the specimen, while stereo microscopes only provide 10 to 40 times the original specimen’s size. A compound microscope gives you the power to see the specimen clearly and closely than ever, allowing you to do things that the naked eye cannot.

Using a compound microscope

There are different types of compound microscopes, and they are used specifically in their line of job applications.

A phase contact compound microscope is a compound microscope that uses a special phase contract objective lens and a phase slider, specialized to bring out the contrast of a sample without having to put coloring to the specimen.

Another type of compound microscope is the polarizing microscope. The polarizing microscope is another type of compound microscope that uses both analyzer and polarizer specifically to cross-polarize the light and gain the differences in the colors. 

To give you more knowledge, here are the step-by-step instructions on how to use and adjust a compound microscope. 


First, you must turn on the illuminator. It is a steady light source, usually coming with a voltage of 110, and is usually used in place of a mirror. If the microscope has a mirror, it can be used to reflect light from an external light source directed through the bottom of the stage. It has a dimmer to adjust the brightness of the light. If you are going to use the dimmer, it is advised to slowly increase the brightness or light intensity because the lamp heats up pretty easily.

Placing the Specimen

The next step is the placement of the specimen. Place the specimen that you want to study above the slide on the stage. Remember to put the sample directly above the aperture. To ensure its stability, fasten it to the stage using the stage clips. Be reminded that coverslip is always needed for better image quality.

The Iris Diaphragm

The next step is about the iris diaphragm. Ensure that the iris diaphragm is completely wide open, as this allows the maximum amount of light to reach the microscope’s lenses and slides. But be careful in using the iris diaphragm, as it cannot be used to adjust the light intensity. Instead, use the dimmer. The iris diaphragm is used to adjust the image resolution and contrast.

The Nosepiece

The next step in operating a compound microscope is about the nosepiece. Before doing anything, you must rotate the nosepiece and adjust it so that the objective lens with the lowest amount of magnification is directly above the specimen. Remember, it is important to use lower magnifications first before adjusting to higher levels to select the part of the specimen before going further.

The Binocular Eyepieces

If you want to study the specimen, you must look at it closer. To do that, you must look into the binocular eyepieces. Once you are looking at the specimen, adjust the iris diaphragm until the light is enough for you to see the specimen. It is always to have more light than less, but be careful as it might hurt your eyes.

The Coarse Adjustment 

If you want better image quality for your specimen, you can turn the coarse adjustment knob because it improves the image’s broad focus. But be careful adjusting this with a high-magnification level of an objective lens, as it may make contact with the specimen.

The Fine Adjustment

After adjusting the coarse knob, you should adjust the fine adjustment knob next. This knob allows you to adjust the specimen’s sharp focus. Turn the knob until you get your desired sharpness of focus. Just be careful adjusting this while using the high-magnification objective lens, as they might get too close and hit the slide.

After all of these, the user should then be able to adjust and recalibrate every adjustment knob according to the viewer’s liking and preferences. 

Remember, every microscope has its own goal and use. Just pick the right microscope for every specific task to gain great results. Remember that the compound microscope is not necessarily the top of the line, but it can give you satisfying and impressive results. They can give you the ability to see the microscopic world when your naked eye cannot. It can be used in a lot of different ways, but just like any other laboratory equipment, the compound microscope also needs the utmost care.