magnification
  • noun a measure of increase in size, especially in the apparent size of an image seen through a microscope
  • The increase in the size of an image provided by a telescope (or microscope). Magnification is measured in linear rather than area terms, so that a planet viewed under a magnification of 200 will seem 200 times larger than with the naked eye (to which it would in fact appear as a point source of light) and would have 40,000 times the apparent area – 200x200. Some small telescopes and binoculars are specified in terms of magnification and lens size, so that 10x50 binoculars have a magnification of 10 and objective lenses 50mm across.

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