Microscopes

• An iris diaphragm controls the amount of light entering the microscope.
• A condenser lens focuses the light onto the specimen, increasing its intensity.
• eyepiece lens


  this is the lens closest to your eye, it usually has a magnifaction of x10
• objective lens


  this is the three different lenses(x4,x10, x40) to magnify the image more to see it clearly
• stage

  this is where the microscope slide is placed with clips to hold it in place
• base


  this is really heavy to hold the wight of the microscope
• coarse focus knob


  it lets you see the image more clearly
• fine focus wheel


  it gives more of a sharp and clear focus
• arm

  holds the eyepiece lens above the stage
• light


  source of light thats reflected off a mirror or glass to show the specimen in the slide
• mirror


  reflects the light into the microscope
• total magnification


  magnification of eyepiece lens x magnification of objective lens
• magnification of an image


  image size/actual size
• Electron microscope


  -uses electron instead of light

  -alive specimens cannot be seen in here as the sample is in a vacuum

  -has a higher resolution and magnification than light microscope

  -is way more expensive

  -takes a lot of time to use
• 1650s 


  Robert Hooke used a compound microscope and analysed specimens
• 1590s


  Janssen a dutch who made spectacles made the first compound microscopes, these are destroyed but were thought to be x3 or x9
• late 1600s

  anotnie van luewenhoek made another microscope with one lens which was x237