Compound Light Microscopes


What is a Compound Microscope? 

Compound Microscope

A compound Light Microscope is a microscope with more than one lens and with its light source. Unlike other microscopes, the picture becomes clearer and more beautiful when you glance through the eyepiece because it has its light source. It has ocular lenses in binocular eyepieces and objective lenses in a rotating nosepiece so you can see the specimen closer and clearer. It is used today with its improved performance in laboratories and hospitals because of its clearer specimens.

Brief History of the Compound Microscope

The first light microscope was invented by two Dutch spectacle makers Zacharias Jansen with his father Hans in 1595. Through his study and experiment with lenses, they developed a compound microscope that uses collapsing tubes to produce magnifications up to 9x.

In today‘s time, the strongest compound microscope has magnifying powers of 1000-2000x. Amazing, right? It is also considered a Bright-Field microscope because of its light source coming from its base. It is also called Bright-Field because it is lit from below and viewed from above by the eyepiece.

Bright field microscope diagram


1. Own light source – because the compound microscope has its light source, it is more convenient to use as it gives a better and clearer view of the specimen’s image.

2. Delivers clear microscopic details – due to factors such as magnification and resolution provided by the compound microscope, the details of the specimens you examine become clearer.

3. Easy to use – it’s easier to use than any other microscope because you can use it quickly by simply plugging in a machine, specifying a specific tool, making a few adjustments for better vision after that you can view it through the viewing heads. 

4. Multiple Lenses – through 1 or more lenses it is better to get out of the details from the viewing heads.

5. Simple to Store – since you can use it without having anything connected to it will make it easier for you to store and release it again when you want to use it.


1. Convex Lenses – a compound microscope has 2 or more convex lenses used to see specimens more clearly. You will see the specimen in the form of a 2-dimensional image.

2. Magnification – is the ability to view objects larger. Having a good image is achievable by placing more specimens for a clearer image. The higher the magnification, the clearer the image will be. The power of the objective lens to see clearer images is 4x, 10x, or 40x then multiply it by the power value of the eyepiece which is typically 10x. For example, if the eyepiece is 10x and the objective lens is 40x, it is equal to 400x magnification.

3. Resolution – like other pictures, resolution refers to how clear the details of an image are.

4. Resolving power – this is the ability to separate objects from other objects that are too small and close to each other.

5. Optical quality – optical quality is the quality of the specimens that you see in the eyepiece of the microscope, but it still depends on the wavelength of light that hits the specimen. The shorter the wavelength or the brighter the light the better and clearer the image resolution becomes.

6. Working distance – as it says, this is how far you check and examine the specimen. The farther you work, the less the magnification or the less viscous the specimen. When your working distance is closer because you want to get a good magnification you need to be careful not to damage the specimen you want to examine.

7. Distortion – is also one of the factors to consider when checking and extracting small specimens. But this is affected when the specimen is free of natural pigmentation to provide contrast when viewing the specimen.

Take note: The compound microscope can view different organisms but is unable to view the molecules, atoms, and viruses that only the Electron Microscope can.


1. Stained Prepared Slides — you can use it when you want to see and examine the bacteria, chromosomes, organelles, blood, and thick tissue sections.

2. Unstained Wet Mounts — this is used in living preparations which enable you to see things such as pond water, living protests, and plant cells.

Viewing Heads

Bright Field microscope

1. Monocular — it uses only one eyepiece when viewing a specimen. When using this viewing head, you cannot use a CCD camera because it can occupy and cover the eyepiece. It is also lightweight, and less expensive than other viewing heads.

2. Binocular — as “bi” refers to two, it has two eyepieces. It is more comfortable to use because you can use two eyes that you can use to see specimens. This is what most microscope users prefer because of its more comfortable use.

3. Trinocular — TRI means three. It has three eyepieces that can be used by two persons because the first person can use the first 2 eyepieces and the last piece can be used by the other person. You can also attach a CCD camera while using two eyepieces. It is more expensive than other viewing heads due to the additional purpose it offers.

Viewing heads can be set to 30 degrees or 40 degrees angle with two adjustments, namely sliding or hinge adjustments for interpapillary distance depending on the person’s preference for viewing the microscope.

If you want to have a better experience in your experiments and studies, it is better to have a compound light microscope because of the many benefits and functions that it can offer you. You just need to be extra careful when handling specimens because damaged specimens can give you a poorer view of them that can cause you problems and mistakes.