Microscope Terms to Know 

^^Dissecting Microscope^^

  • a microscope in which a 3-dimensional object is observed using reflective light

^^Compound Microscope^^

  • a microscope in which the object to be observed is mounted on a flat glass slide and observed using light transmitted through it. the image in a compound microscope is effectively 2-dimensional

Compound Microscope Terms:

^^Aperture Diaphragm^^

  • regulates light intensity (it is located just under the stage)
  • can be adjusted to control the amount of light transmitted through the slide
  • turn on light source, locate the lever on the diaphragm, and look through the microscope
  • open and close the diaphragm by moving the lever back and forth
  • if your field of view is too dark, open the diaphragm more
  • common problem: if someone has left the diaphragm wide open, your specimen will be flooded with light and will be difficult to see. when you first use the microscope, close the diaphragm and slowly open it up to a light level that is comfortable for viewing

^^Arm^^

  • the supporting body of the microscope

^^Coarse Focus adjustment knob^^

  • adjusts the coarse focusing
  • with the low power objective in place, move the coarse adjustment knob while viewing from the side
  • the lens move up and down very quickly and this control is only used with the low power (4X) objective

^^Condenser^^

  • a lens system used to focus the light beam up into the iris, and the slide
  • for your purposes, the condenser should be positioned high, with its uppermost lens just beneath the slide on the stage
  • practice moving the condenser up and down but leave it in the high position

^^Eyepiece or Oculars^^

  • house of ocular lenses
  • some oculars have a pointer, which gives a point of reference for finding structures
  • on binocular microscopes, you can also adjust the distance between the oculars to accommodate the distance between your pupils by gently sliding or pushing the oculars

^^Field Diameter^^

  • the diameter of the microscope’s field of view

^^Fine Focus adjustment knob^^

  • adjusts the fine focus
  • once you have an object in focus under the scope, use the fine adjustment to better focus the image for viewing
  • carefully adjust this control while looking at the lens from the side
  • note that it does not move up and down as quickly as the coarse control
  • use this adjustment with the 10X and 40X objective lenses

^^Lamp^^

  • the light source is incorporated into the base of the microscope
  • before turning it on, make sure the light intensity dial is set to its lowest setting to prolong the life of the bulb
  • if you suspect the bulb has burned out, contact your instructor for assistance

^^Magnification^^

  • calculated as the ocular power multiplied by the objective power

^^Objective Lenses^^

  • a set of lenses of various magnification powers
  • note that the lowest power lens has the shortest tube but provides the largest viewing diameter

^^Stage^^

  • the platform on which the microscope slide is placed under the objective lens
  • note the hole in the stage that allows light to pass up through the specimen on the slide

^^Stage Clip^^

  • secures your slide for viewing

^^Stage movement controls^^

  • allow you to move the slide about on the stage

^^Revolving Nosepiece^^

  • the mount for the objective lenses; revolves to bring the various objective lenses into position for viewing the object

^^Working Distance^^

  • the distance between a lens and an in-focus subject
  • the smaller the objective lens and the lower the magnification, the larger the working distance