Types of Optical Microscopes

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  A microscope will make items visible that are too small to see with the naked eye. An optical microscope uses light to enhance the magnification process. The first optical microscopes date back to the late 16th century. Today, there are three principal classifications of optical microscopes: monocular, binocular, and stereo microscopes.

Monocular

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  Monocular microscopes create a single image, through the use of one or more lenses. A magnifying glass can be classified as the simplest type of monocular microscope. It utilizes only one lens.

  When a microscope uses more than one lens, it is called a compound microscope. The first lens is contained in the eye piece. The eyepiece is connected to a long tube. The objective lens is attached to the opposite end of the long tube.

  The light source shines from under the specimen and through both tubular lenses. This magnifies the image in the viewer's eye. Adding more lenses creates higher magnification of the specimen. Most students utilize the monocular microscope.

Binocular Microscopes

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  A binocular microscope uses one objective lens, but two eyepieces. The image from the first lens is split by a prism to allow both eyes to see the same image. This is a two dimensional image.

Stereo Microscopes

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  Stereo microscopes were developed in the early 20th century. They were primarily developed to aid in the process of ballistics testing. Today, stereo microscopes are most commonly used to compare larger specimens to each other.

  These microscopes achieve an enhanced image through the utilization of two sets of lenses, and two eye pieces. The angles of the objective lenses can be changed to show either two objects side by side, or one object from different angles, creating a 3-D image.

Modern Advancements

• In recent years, digital video has been used to enhance the imaging of optical microscopes. Modern advancements have also included the utilization of new light sources. Fiber optic, ultra violet and infrared light are now used to enhance the effectiveness of microscopes. Metallographic and anastigmatic photo lenses are also used to aid in the enhancement of images.