The most basic type of optical microscope is the magnifying glass. It is best to know all the different microscope parts before purchasing a microscope so that you can choose the one that is best for you.
Eyepiece Lens – This is the part of the microscope that the user actually uses to look through onto the object that is being magnified. The eyepiece lens is typically the same in most microscopes except for the children’s microscope when the eyepiece lens will be built in a smaller form in order to accommodate a smaller viewers face proportions.
Objective Lenses – The objective lenses are the second set of lenses in a compound microscope. There are usually a variety of strengths of objective lenses on any one given microscope. The objective lens will usually range in magnification strength from 4X to 100X. When the objective lens is combined with the power of the eyepiece lens, then the magnification power is times by the amount of the two lenses combined. So if your eyepiece lens is 10X in strength and you combine that with your objective lens which is 100X in strength, then you will get the magnification power of 1000X.
Tube – The tube is responsible for connecting together the eyepiece lens and the objective lens. This is a very basic part of the microscope and only serves one single purpose. The functionality of this piece will usually never vary other than connecting the two lenses and occasionally it will also house some type of adjustment knob on the microscope.
Arm – The arm is responsible for supporting the tube and allowing the tube to be connected to the base of the microscope. The arm has no other function other than supporting the tube.
Stage – This is the place where you actually place your slide onto. The stage usually has two clips on it that are used to secure the slide to the surface of the slide. Some microscopes have a mechanical stage which allows the user to actually move the slide around using knobs instead of manually positioning the slide by hand.
Revolving Nosepiece (Turret) – This piece is used to rotate multiple objective lenses on one single microscope. This is used when you need to select the amount of magnifying power that you want to use.
Rack Stop – This part of the microscope is used to prevent the user from bringing the objective lens down to close to the slide that it breaks or damages something. This setting is set at the factory and cannot be adjusted.
Those are the most basic and common parts of a pocket microscope and you should take the time to check out each one before purchasing your microscope. Knowing all the parts of the microscope is a good way to figure out which one will work best for you.