Using a compound microscope

• Body Tube: hollow tube which light travels from objective lens to the ocular lens

  
• Revolving Nosepiece: rotates through different objective lenses of different magnification
• Objective: gathers light from the specimen, magnifies the image of the specimen and project the magnified image into the body tube

  
• Stage Clips: spring loaded clips that hold the stage in place

  
• Diaphragm: concentrates light correctly on the specimen and direct the light rays into the objective lens

  
• Lamp/Mirror: illuminates the specimen on the stage

  
• Eyepiece/Ocular lens: further magnifies the image and focuses the light on the retina of the eye

  
• Arm: supports the microscope and attaches the body tube and the base

  
• Stage: horizontal surface that holds the slide and specimen

  
• Coarse Adjustment Knob: quickly moves the stage up and down to focus the specimen

  • ONLY used on low power objective lenses

  
• Fine Adjustment Knob: slowly moves the stage up and down to focus the specimen

  • can be used on high power objective lenses

  
• Base: supports the entire microscope

  
• Total Magnification: Magnification of Ocular Lens x Magnification of Objective Lens

  • e.i. What is the total magnification of an image if the ocular lens has a magnification of 10x and the objective lens has a magnification of 25x?

  Total Magnification = (10x)(25x)

  = 250x
• Field of View Diameter: distance across the viewing field under the objective lens

  FOV 1 x Mag 1 = FOV 2 x Mag 2

  
• Calculating Size of Object:

  Size of Object (SOO) = FOV / Fit #

  • FOV = field of View
  • Fit # = the number of times an object appears to fit across the field diameter

  
• Calculating Scale of Drawing:

  Scale of Drawing: Size of Drawing (SOD) / Size of Object (SOO)

  • make sure that both numbers are written in the same units