Light microscopes depend on light being reflected by the particles of the substance being studied. However, sometimes the particles are too small to noticeably reflect the light. Electron microscopes function by sending a beam of electrons through a subject; electrons are so tiny that anything can reflect them.
The wavelength of an electron is much smaller than the wavelength of visible light.
the use of electrons instead of light
Blue wavelengths provide better resolution.
A compound microscope consists of several lenses operating together, whereas a simple microscope is one lens, like a magnifying glass. A compound microscope gives higher magnification and also better resolution than a simple microscope.
Stereoscopic microscopes, also called low-power microscopes, dissection microscopes, or inspection microscopes, are designed for viewing "large" objects at low magnifications. Unlike a compound microscope which provides an inverted 2-dimensional image, stereo microscopes provide an erect (upright and unreversed) stereoscopic (3-dimensional) image......
Its electron microscope which has the greates resolution power and is up to 0.1 nanometer i.e. 1x1010 and magnify upto 100,000 times.
compound light microscope
A compound microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy. Microscopic means invisible to the eye unless aided by a microscope. An electron microscope is a type of microscope that uses a beam of electrons to illuminate the specimen and produce a magnified image. Electron microscopes (EM) have a greater resolving power than a light-powered optical microscope, because electrons have wavelengths about 100,000 times shorter than visible light (photons), and can achieve better than 50 pm resolution[1] and magnifications of up to about 10,000,000x, whereas ordinary, non-confocal light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications below 2000x.
A compound light microscope is limited to about 2000X magnification.
Blue wavelengths provide better resolution.
A compound microscope consists of several lenses operating together, whereas a simple microscope is one lens, like a magnifying glass. A compound microscope gives higher magnification and also better resolution than a simple microscope.
That is not for every micro organism.For some microbes,high resolution power is needed.
Electron microscopes are more powerful in terms of magnification, compared to compound microscopes. They are capable of two million-power magnification, while compound microscopes are only capable of 1000x magnification.
Stereoscopic microscopes, also called low-power microscopes, dissection microscopes, or inspection microscopes, are designed for viewing "large" objects at low magnifications. Unlike a compound microscope which provides an inverted 2-dimensional image, stereo microscopes provide an erect (upright and unreversed) stereoscopic (3-dimensional) image......
A compound microscope is enough to observe a bacterium. But as per the need of clarity & resolution ,one can use electron microscope etc.
A compound microscope
Optical, though to see smaller organelles and structures in higher resolution an electron microscope may be necessary.
Resolution of a microscope is tied to the numerical aperture of the objective lens and the condenser but is influenced by other factors, such as alignment, type of specimen, wavelength of light, and contrast enhancing techniques. Read more: Define Resolution in Microscopes | eHow.com http://www.ehow.com/facts_5753341_define-resolution-microscopes.html#ixzz1kYyrj6D9
Its electron microscope which has the greates resolution power and is up to 0.1 nanometer i.e. 1x1010 and magnify upto 100,000 times.