1.3 Microscopy - What it is

• Parts of a light microscope:

  • Base: supports the entire microscope at the bottom
  • Arm: connects the bottom to the top
  • Light source: can be a lamp or mirror to reflect light from the room
  • Stage: where the microscope slide is placed
  • Lenses in the top half:
  • Three objective lenses with different magnifications (e.g. 10x, 20x, 50x)
  • Eyepiece lens with fixed magnification at the top for viewing
  • Body tube
  • Coarse and fine focusing knobs to adjust focus
• Object vs. Image in microscopy:

  • Object: the real object or sample being viewed (e.g. onion cells on a slide)
  • Image: what is seen when looking through the microscope (e.g. image of onion cells)
  • Light from the room hits the mirror, passes through the object, lenses, and into the eye to create an enlarged image
• Magnification:

  • Definition: how many times larger the image is than the object
  • Equation: Magnification = Image size / Object size
  • Higher magnification means the image appears larger
• Resolution:

  • Definition: shortest distance between two points on an object that can still be distinguished as separate entities
  • Higher resolution means more detail and less blurriness in the image