PreviousNextChapter 1 PartsChapter 1PartsC.Robert Bagnell,Jr.,Ph.D.,2000Figure 1.1 illustrates the parts of an upright compound microscope and indicates theterminology that I use in these notes.EyepieceBinocular TubeStandNosepieceObjectiveCenteringBulbCondenser IrisCenteringCondenserCentering KnobFlip In LensField IrisCondenser FocusFilters Collector LensMicroscope FocusFocusFigure 1.1.-Parts of a Compound Light MicroscopeStandThe Stand is the solid support for the optics and mechanical parts of themicroscope.Over the years manufacturers have adopted many different configurations forthe stand.Regardless of the exact style,there are two basic types:The upright stand hasthe objective lenses facing downward.The inverted stand has the objective lenses facingupward.Illumination SystemThe old microscopists believed that the best illumination came from the north sky.Itwas focused on the specimen by use of a concave mirror.It was a beautiful light with aremarkably constant color.It had drawbacks.The light did fluctuate in intensity,especiallyon cloudy days,and you couldn't work at night.Artificial light sources are moreconvenient and these are the types I will discuss.The color and intensity of light,and the way it is brought to the specimen,whetheras diverging,converging,or parallel rays,greatly influences the appearance and resolutionof the specimen.Kohler IlluminationIn the late 1800's,August Kohler invented an illumination technique that was soprofound it is still the standard method used today.Modern microscopes are designed touse Kohler illumination.Kohler illumination uses optics that place the image of the filamentin the back focal plane of the objective lens.This results in the light source beingPathology 164-Light Microscopy