What are the parts of a microscope?

Every microscope consists of multiple key parts all working together to not only view specimens, but also magnify them. There are structural, optical, and illumination components all playing an integral role in the proper functioning of your microscope. We’ll explore the parts of a microscope below.

Basic Microscope Parts

Any microscope from pocket microscopes to laboratory compound microscopes all have these basic parts: eyepiece, objective, light source, focus knob and drawtube.

• Eyepiece
  The eyepiece lens on a microscope is the part of the optical system where you place your eye to view the magnified object. In something like a pocket microscope, the eyepiece may not be adjustable or removable in any way, but in compound microscopes you can replace and upgrade them as you wish. There is so much to know about eyepieces we made a separate article on that topic called “Helpful Guide for Everything to Know About Microscope Eyepieces”.
• Objective
  The objective lens on a microscope is part of the optical system that’s responsible for producing a magnified image of the specimen being viewed. It’s the lens closest to the specimen and is positioned at the bottom of the microscope’s nosepiece...
• Light Source / Illumination
  Every microscope needs a light to see your object. This applies to a digital microscope to a pocket microscope to a compound microscope...
• Focus Knob
  Except for some fixed power pocket microscopes that have a preset and fixed focus, every light microscope has a focus knob...
• Drawtube
  The drawtube is the optical tube on the microscope that holds the eyepiece...

Breaking Down the Elements of a Microscope Beyond Its Standard Parts

Microscope construction incorporates structural, optical, and illumination sections that all work together...

Structural Parts of a Microscope

• Body Tube
  Not to be confused with the drawtube, the body tube is the main piece where the lens system lives...
• Revolving Nosepiece
  The revolving nosepiece holds the objective lenses so the user can quickly rotate them...
• Head
  A microscope always has a head. It’s where the eyepiece sits...
• Base
  A microscope’s base is the flat bottom part providing the foundation of stability...
• Arm
  It connects the eyepiece to the base of the microscope...
• Stage
  The stage is the platform where you place your specimen or slide...
  • Mechanical Stage
    The mechanical stage of a microscope is a platform that holds the slide containing the specimen...
  • Slide Holder
    This is where the slide sits and is retained.
  • Slide/Stage Clip
    The clips keep slides in the correct position...
  • Stage Lock
    You can lock the stage down with the tightening screw.
  • Stage Opening
    The stage opening provides a hole to allow the light to pass up...
  • Graduated Locator Markings
    This is a special ruler that allows you to measure movements and positions...
    • How do I employ graduated locator markings to measure an object when using a mechanical stage?
      1. If you move the stage by turning the mechanical stage knobs...
      2. If you subtract the difference, you know exactly how far you moved...
      3. Then center the left side of an object, take a measurement.
      4. Center the right side of an object, take a measurement.
      5. The difference is the width of that object.
    • How do I measure using a Vernier scale?
      1. Take the measurement off the main scale...
      2. Where they line up is the additional measurement.

      In the photo example, the main measurement is the 2 from the 20 mm measurement.

      • The 0 on the Vernier scale doesn’t pass the first line, so the measurement is 20 mm...
      • If it was past the first line, then the base measurement would be 21 mm...
      • For the next decimal place, the Vernier scale lines up at the third line, so 0.3 mm...

Microscope’s Optical Parts

• Eyepiece
  You can review this above under the Basic Microscope Parts section of this article.
• Objective Lenses
  You can review this above under the Basic Microscope Parts section of this article.
• Condenser & Condenser Lens
  The condenser is an optical component located below the stage...
• Iris Diaphragm
  The iris diaphragm is usually one of the most forgotten about but powerful parts...
• Filters
  Filters are an optional part of a microscope...
  • Filter Wheel
    Some microscopes have pre-installed filter wheels...
  • Filter Holder
    Most compound microscopes just have a single filter holder...
  • How do I install a filter on a microscope?
    Filter holders are typically under the condenser lens...
• Adjustment Knobs
  Coarse and fine focus knobs control the vertical movement of a stage...
• XY Control Knobs/Mechanical Stage Knobs
  These knobs move the slide left to right on the X axis...

Illumination Parts of a Microscope

• Light Source/Illuminator
  The light source/illuminator provides a controlled and focused beam of light.
• Mirror
  The mirror reflects and directs light onto your specimen...
• Rack Stop
  An important safety feature limits the objective lens’s vertical movement...

Now you know your microscope from top to bottom, or from eyepiece to base! Still have questions? Our customer care team is happy to help!