Calculations

• What is the equation for magnification?

  $Magnification=$$\frac{image\ size}{actual\ size}$
• What is magnification?

  How many times bigger the image is when compared to the object
• What is resolution?

  The minimum distance apart that two objects can be in order for them to appear as separate items
• How do you convert mm into $\mu m$?


  Multiply by 1000

  E.g. 3.6mm=3600$\mu m$
• How do you convert nm into $\mu m$?


  Divide by 1000

  E.g. 500nm= 0.5$\mu m$
• What is the eyepiece graticule used for?

  This can be used to measure the size of objects you are viewing under the microscope.
• How do you calibrate the eyepiece graticule?

  • Use a stage micrometer
  • Step 1 - Line up the stage micrometer and eyepiece graticule whilst looking through the eyepiece.
  • Step 2 – Count how many divisions on the eyepiece graticule fit into one division on the micrometer scale.
  • Step 3 – Each division on the micrometer is 10µm, so this can be used to calculate what one division on the eyepiece graticule is at that current magnification