differences between a light and electron microscope
Although the theory between an optical and electron microscope is similar, the results that can be achieved vary tremendously. This is due to several factors but the most important of these being the resolution it is possible to achieve using the different microscopes. With an ordinary light microscope the average resolution achievable is 300 nm (m x 10-9) with an electron microscope this is increased to 10 nm. The reason the resolution varies so much is that the resolution is calculated by halving the wavelength of the power source in light microscopy this is the wavelength of visible light between 400 and 700 nm. Electrons have a much shorter wavelength of about 0.005 nm.

Electron microscopy uses electrons with energies of a few thousand electron volts energies 1000 times greater than visible light. The reason that the average resolution is greater than this number is due to the construction of the microscope it’s self, however the resolution can be pushed to 0.1 nm.

Another thing which contrasts between light microscopes is the depth of field this is poor on light microscopes, but in high on electron microscopes. Also the Field of view between the microscopes varies greatly it is good on both the light and electron.

As the surrounding for the electron microscope is a vacuum it follows that they are it is unsuitable for the magnification of living things. A light microscope can be used to look at real living or non-living items.

The contents of a light and electron microscopes differ, but only slightly. Both types of microscope contain the following objects: Condenser lens (magnetic coil in EM), specimen holder and objective lens (magnetic coil in EM). The electron microscope (EM) contains a projector lens, which is made of magnetic coil.

Magnification in the electron microscope can be varied from hundreds to several hundred thousands of times. This is done by varying the strength of the projector lens. This can not be achieved with a light microscope.

The cost of each microscope also varies, light microscopes tend to be quite inexpensive, this allows any one interested in microscopy to purchase a light microscope. Electron microscopes however prove to be expensive (around 1 million pound each), this doesn’t allow many people interested

Disadvantages of all electron microscopy are that the samples have to be cut incredibly thin (usually with a glass or diamond knife) so the electrons will collide with them. Also there is no guarantee that what goes into the microscope is reality, as to see the objects detail more clearly the objects have to be heavily stained with a metal (usually uranium) and there is no guarantee that this does not damage the samples. If the staining does not damage the sample it is likely that the heavy metal salts used to melt away the electrons will.

The main difference between light and electron microscopes is the amount of resolution that can be achieved with electron microscopes to light microscopes. The main similarities are the contents within the microscopes.

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