Magnification

  

• Resolution: The ability to distinguish between two separate points, Electron microscopes have a higher resolution than light microscopes as they use electrons, as they use electrons (which has a shorter resolution than light). Shorter resolutions allow for better resolution than longer wavelength. Some times microscopes have blue filters to allow for this as blue has the shortest wavelength. 
• Magnification: Indicates how much bigger the image is than the original object. Simply given as a magnification factor e.g. x100, By using more lenses microscopes can magnify by a larger amount, but the image may get more blurred, so doesn't mean that more detail can be seen.
• Light Microscopes: Oldest, simplest, and most widely used microscopes. Specimens illuminated with light, which is focused using glass lenses and viewed using the eye or photographic film. Specimens can be alive or dead, but often need to be stained with colour to make them visible. 
• Electron Microscopes: This uses a beam of electrons, rather than electromagnetic radiation, to “illuminate” the specimen. Electrons behave like waves and can be easily produced (using a hot wire), focused (using electromagnets) and detected (Phosphor screen or photographic film). A beam of electrons has a very useful wavelength of less than 1nm, so can be used to view sub cellular specimens. 
• Transmission Electron microscopes (TEM): work like light microscopes, transmitting a beam of electrons through a thin specimen and then focussing the electrons to form an image on the screen or on a film. This is the most common form of electron microscopes and has the best resolution (<1nm)
• Scanning Electron microscopes (SEM): scan a fine beam of electrons onto a specimen and collect the electrons scattered by the surface, this gives poorer resolution, but means you can view the final image in 3D.