Compound Microscopes

Microscopes are used to view things that cannot be seen with the unaided human eye. Microscopes are available in many sizes and types depending on what you want to do. Some can magnify the specimen up to 10000 times normal size or more in some cases.Usually the maximum magnification of a compound scope is around 1500X.

When it comes to microscopes, you have many choices depending on what you need to accomplish with it. Factors include magnification, type of light used and how the specimen is displayed.

The first microscope ever invented is credited to Zacharias Janssen around 1590. Robert Hooke improved the design about 1660 and started building compound microscopes. Anton Von Leeuwenhoek is credited with building only simple (single lens) microscopes, but they were the best ones created at the time.

By far, the most widely used type of microscope is the compound microscope, also called a compound light microscope. This type of microscope derives it’s name from the fact that it uses a series of lenses to view the specimen which is situated between the lenses and a light source.

The compound light microscope uses what is called light absorption to display the image. All this means is that light is used to illuminate the glass slide, thus making the image visible under magnification.

Very simple to use, compound light microscopes are extremely common and lower priced versions are sold in hobby shops and toy stores.

Compound microscopes have a lens that you look into that leads to another lens on the nosepiece, which is down closer to the specimen. Like looking through a telescope, only on a smaller scale. This determines the magnification level of the specimen.

The magnification level depends on which of the lenses on the nosepiece that you are using. Let’s say that the eyepiece you are using is a 10X eyepiece and the lenses on the nosepiece are 15X, 30X and 50X. If you use the 15X lens, then you are seeing the image at 150X (10x X 15x) it’s normal diameter or size. Use the 50X lens and the magnification is now 500X (10x X 50x) original size.

To focus the image, there are two adjustment knobs designated as coarse on the stage (specimen holder) and fine on the eyepiece. The coarse adjustment is used to raise or lower the specimen on the stage. The fine adjustment is used to sharpen the image.

Compound microscopes are used widely in middle and high school labs. Children everywhere have enjoyed looking at ordinary things like human hair, plant leaves and other things that can be found close to the classroom. Prepared slides are available that have images of blood cells, skin cells and many others.

Again, these compound microscopes are the most widely used of all the types and can be found at hobby shops and toy stores. Of course, for a higher quality microscope, you should look at a professional equipment warehouse.