Parts of a Microscope

The Pieces of a Compound Microscope   

In the history books, it is stated that somewhere around 1590, a Dutch spectacle maker by the name of Zacharias Janssen is said to have come up with the first compound microscope. The compound microscope utilizes light and lenses to make the image bigger, and because of this, it is sometimes called an optical or light microscope.  

The magnifying glass is the least complicated, light microscope, and it can magnify things ten times (10X). There are two types of lenses that make up the compound microscope, and these allow for more viewing. The first lens is the ocular which is also called the eyepiece, and second, the objective lens which is the lens that is the closest to the object to be viewed. 

Anyone who buys a microscope should be familiar with all of its features. 

Ocular Lens or Eyepiece:  This is what you look through. Typically 10X or 15X.  

Objective Lenses:  Typically a microscope has either three or four objective lenses. Most of the time, they are 4X, 10X, 40X, and 100X magnification.  Added to a 10X ocular lens, then users have the option to view in the follow magnifications: 40X, 100X, 400X, and 1000X.  

In order to see clearly at 1000X, a highly developed microscope with an Abbe condenser must be used. The lens with the smallest length has the least power, and as to be expected, the longest lens has the most power. Lenses can be recognized by their colors, and if they are constructed accorded to DIN regulations, they can be fixed to different microscopes. 

To protect themselves from harm, the lenses which are high power can dart back inside. For instance, if they accidently come into contact with a slide, the edge of the lens will retract, protecting itself, the slide, and the contents. Any superior microscope will have the best parfocal lenses. 

Tube:  This links the objective lenses to the eyepiece 

Arm:  Provides support to the tube and ties it to the base 

Base:  This is the lower portion of the microscope which offers support 

Illuminator:  A 100 volts light which provides a steady stream of light energy. It takes over for the mirror.  

Stage:  This is where the slides go. They are held in place by clips. Depending on the type of stage your microscope has, you might be able to move the slide around for better viewing.  

Turret or Revolving Nosepiece:  This feature cannot be missed; it is the place where the objective lenses and held. The nosepiece rotates so that the lenses can be easily rotated. 

Rack Stop:  This is a stop set by the manufacturers; it determines how low the objective lenses can get. It is locked in this position so that slides will not be broken by those who cannot understand the distance between the objectives and the slide. The rack stop can be adjusted if necessary, but it is not encouraged. Rather than adjust it for thin slides, it is easier to just place another transparent slide under the thin one to make it higher. 

Condenser Lens:  This lens works by drawing the light onto the slide content. The lenses work best at the greatest powers, 400X and higher.  

Iris or Diaphragm:  Under the stage, quite a few microscopes house a disk that moves around. This iris or diaphragm has various holes in it, and it is positioned at specific holes in order to direct a certain amount of light to the slide. 

Instructions to Focus Your Microscope:  To focus your microscope, you always begin with the lowest objective. As you look, you should move the lens down as close to the slide as you can without actually touching it. Once this is done, a person should glance through the eyepiece and focus the eyes in an upward direction until the picture is vivid.  

If the picture does not become sharp and in focus, that entire process can be repeated. Once the picture is clearly seen, then you can rotate to the next power lens and adjust your focus as needed. You can continue to do this until you have seen everything you wish to see. 

Finding the Right Microscope: When you look for a professional microscope that gives you vivid, clear pictures, you should avoid toy stores and cheap plastic knock-offs that boast of magnifying specimens at 600X and higher. A high quality microscope will have a metal body and lenses that are made of glass. 

One of the best ways to find a great microscope is by getting one from a highly respected dealer. Some fly by night dealers might give you one price, but then be closed two months from now. You really need to find a dealer who has been in business for a long time and offers great customer service. One popular, highly rated online dealer is Microscope World. Great prices, great service, and a great inventory.