used microscopes are optical microscopes that use single lens with
different magnifying powers, which will depend on the lens being used
for a particular microscope. Optical
microscopes use visible light to create a magnified image.
convex lenses, which are generally used in such microscopes, can magnify
an object up to fifteen times its original size. In a compound
microscope, two lenses are mounted at the opposite ends of a closed
tube. Magnification is thus increased several times over and can even
reach to two thousand times the original size.
you may recall from your biology lab class, objects that are viewed
under microscopes are mounted on slides, or transparent strips of glass.
We can take photographs through a microscope. For this, a camera takes
the place of our eye at the microscope. Three-dimensional images can
also be seen through a microscope. For this purpose, two low-powered
microscopes are arranged in a certain manner.
objects cannot be viewed under normal illumination. Under such
circumstances a dark-field microscope is used. The type of illumination
provided by this microscope enables viewing of the desired images.
Richard Adolf Zsigmondy (1865-1929) was an Austrian-born German chemist
and Nobel laureate. To him goes the credit of developing an
ultra-microscope with a dark field illumination.