microscopes magnification, field of view and estimating size
Post on 24-Dec-2015
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Microscopes
Magnification, Field of View and Estimating Size
Eyepiece or Ocular Lens
Coarse Focus Knob
Fine Focus Knob
Arm
Stage Clips
Base
Revolving Nosepiece
High Power Objective Lens (40X)
Lower Power Objective Lens (10X)
Stage
Diaphragm
Light / Mirror
Body Tube
Magnification• Total magnification is how large the specimen appears under
the microscope
Total magnification = Eyepiece (ocular) x objective lens
Objective Lens Selected
Magnification of Objective Lens
Magnification of Eyepiece (ocular)
Total Magnification
Scanning
Low Power
High Power
4X
10X
40X
10X
10X
10X
40X
100X
400X
• How much more powerful is high power compared to the low power in terms of total magnification?
• How much more powerful is high power compared to the scanning in terms of total magnification?
Field of View• The field of view is the white circle you see
through the microscope• As you increase magnification the field of view
decreases
Estimating Size Under a Microscope
• The field of view will have a different diameter depending on which objective you are using
• Scanning is usually a few millimeters in diameter, low and high objective are smaller
• 1mm = 1000 micrometers (μm) or microns
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