Basic Microscope Anatomy

• Optical microscopes are fairly simple, consisting of a sturdy base, an adjustable arm, a stage for the specimen, a focusing knob, an eyepiece lens and an objective lens. Some have electrical light sources, while inexpensive models make use of a mirror and available room light.
  
  

Eyepiece Lenses

• The eyepiece lens is at the top of the microscope, and is where you look into the microscope. The eyepiece usually has some magnification, typically 10x or 15x power.
  
  

Objective Lenses

• The objective lenses are used to magnify the image of the specimen. Three or four lenses are mounted on a rotating base, and include a low, medium and high magnification lens.
  
  

Specimen Stage

• A sturdy specimen stage is mounted to the base of the microscope. There is a hole in the stage to allow light to pass through the specimen from the bottom. This light enters the objective lenses and eyepiece lens, and is focused by a knob mounted to the microscope arm.
  
  

Stereo Microscopes

• Stereo microscopes feature two eyepiece lenses and two objective lenses. A stereo microscope allows the user to view specimens in three dimensions and is often used in microsurgery.
  
  

Electron Microscopes

• Electron microscopes use a beam of electrons instead of light to illuminate a specimen. Transmission electron microscopes produce very high magnification images. Scanning electron microscopes yield three-dimensional images.