Types of Microscopes Microscopes Rule!!!!!!!!!! There are four basic kinds of microscopes: • • • • Optical (or light) Electron Scanning Probe Ion OPTICAL MICROSCOPES • Optical microscopes are the kind we use in school. • They use lenses to refract the light rays that either shine through or reflect off of the specimen being observed. Optical continued: • Scientists can use special optical telescopes to study details that are not normally visible. • Phase Contrast Microscopes. You study transparent objects with these. This microscope changes how light passes through objects so that thick parts appear one color and thin parts appear a different color. • Dark Field Microscopes. This kind keeps light from shining directly up the body tube. The specimen appears bright against a black background. • Scanning Optical Microscopes. These use a laser beam that scans back and forth over the object. A computer creates the image which is seen on a monitor. ELECTRON MICROSCOPES • An electron microscope uses a beam of electrons instead of a beam of light. Because electrons are so tiny , these microscopes show much finer detail than optical telescopes. You will learn more about these microscopes at the next station. SCANNING PROBE MICROSCOPE • A scanning probe microscope scans a specimen with a sharp point called a probe. • The probe does not quite touch the specimen. • An electric current flows between the probe and the specimen. • A computer uses measurements of the current to create an image. ION MICROSCOPE • Ion microscopes are used to examine metals. • An ion microscope magnifies with such sharpness that individual atoms may be seen. • The metal to be examined is made into a tiny needle. • This microscope works on the principle of electrical attraction and repulsion. Although there are different kinds of microscopes, they are all used for the same purpose: To make something look BIGGER!