Monday, May 18, 2009

Four Types Of Microscopes

Microscopes are imaging aids that allow us to see detailed pictures of objects too small to be seen with the naked eye. These scientific instruments come in different power magnifications. Without these instruments, it is unlikely we would be as advanced as we are in fields such as microbiology, physics and medicine.


Compound microscope


History of the Microscope


Microscopes go back some 400 years, to the the late 16th or early 17th century. There is still debate on who actually invented the instrument. According to New World Encyclopedia, credit has been given to three different eyeglass makers from the Netherlands: Hans Lippershey, Hans Janssen and Zacharias Janssen. Galileo Galilei, in the 1600s, also invented a compound microscope contributing to the field of microscopy. His device used lenses that were concave and convex in shape.


Types of Microscopes


Microscopes fall into basically three categories: compound, electron and confocal. Four of the several types within these categories of microscopes are the compound, digital, electron and stereo microscopes.


Compound microscopes are the most common and the kind you are most likely to see in a science classroom.


A digital microscope has a camera device attached to it called a CCD that is connected to a computer. These microscopes do not have eyepiece viewing ports.


An electron microscope has the highest image magnification.


A stereo microscope uses two eyepieces that are set at slightly different angles, giving the viewer a 3D picture of the object being looked at.


Different Uses of Microscopes


Microscopes can be found in laboratories all over the world. What is being studied and how much resolution is needed to define the object of concern dictates which type of microscope is used.


If you just wanted to look at a leaf under lower magnification, a compound microscope would be appropriate. They magnify images up to 1,500 times. However, looking at atoms and cell parts requires a much more powerful electron microscope able to magnify the image up to two million times its original size.


Smallest Object Ever Seen with a Microscope


Electron microscope


The smallest object ever seen was a radium atom using an electron microscope, but the picture was fuzzy looking.


The microscope has "extended our vision into the realm of sub-cellular organelles, viruses, proteins, DNA, molecules and even atoms," says Interactive Nano-Visualization in Science and Engineering Education's Size and Scale website.


As these tools of science advance, our ability to see smaller and smaller objects may bring us closer to discovering the essence of life.


Other Types of Microscopes


Microscopic view of cells


Some of the new microscope designs, including more advanced electron, scanning probe, field ion and acoustic microscopes, use various imaging methods to illuminate the details of the objects being studied.







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