- The resolution of a microscope is the ability to clearly determine two separate points, or objects, as singular, distinguished entities. If closer together than appropriate for your resolution, the objects or points will blur together, making it impossible to differentiate. Adjust the resolution with the resolving power of the lens of the microscope. Resolution is not magnification, which is a microscope's ability to increase size--not clarity. Magnification also utilizes lenses, but if the resolving power is poor, increasing magnification will only magnify a blurry specimen.
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Though some microscopic scientists recommend 0.2 microns=200 nm as the best resolution for an optical microscope, it is useful to have some simple guidelines for selecting resolution.
Consider whether the resolution of the microscope could damage the subject. If the resolution is very high, for example, the lens will require oil or other liquids that can harm ill-prepared slides or specimens.
Measure the size of the lens against the specimen's size. If the lens is too big, it can crush the specimen.
Select a resolution that shows the largest amount of the specimen. Increase resolution if only a small part is visible in the corner of the eye piece. Use the resolution that allows for the most clear view of the specimen.
More light will be needed each time the resolution is increased, and if more light is not available, it is best to select a lower degree of resolution. - Because the resolution of an optical microscope depends on focused light and light waves, the traditional microscope has been abandoned in favor of electron and scanning probe microscopes. The first man to reveal the limitations of the optical microscope was the 19th-century scientist Ernst Abbe, who stated that light could not be focused on an infinitely small spot. Trying to do this would blur the image by diffraction. The smallest possible spot would measure approximately a third of a wavelength, or about 200nm. This had been universally accepted and practiced, until recently. In 1999, scientists at the Max Planck Institute for Biophysical Chemistry in Goettingen, Germany, bypassed the limit of the wave nature of light by using two laser beams. One beam focused light on the specimen, while the other made an imprint of the fluorescence spot created by the first. This allows for resolution as accurate as a few tens of nanometers and is operable in a three- or four-level energy system
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