The Microscope • Simple Microscope – one lens • Ex – Magnifying lens • Compound Microscope – 2 lenses that “compound” or magnify each other. • Dissecting Microscope – no special slide preparation
Continued… • Eyepiece: • Magnifies material being viewed by 10X • The part of the microscope you look into • Sometimes contains a pointer that can be seen as you look into the eyepiece. • May also be called the ocular.
Continued… • Revolving Nose piece: • Part of microscope to which the objectives are attached • Rotates to allow for the changing of objectives to increase or decrease magnification.
Continued… • Arm: • A secure part of the microscope to hold on to when the microscope is being carried.
Continued… • Objectives: • Low (4x) • Medium (10x) • High (40x)
Continued… • Stage: • Platform on which microscope slide rests • Mechanical Slide Adjuster • Used for adjusting the position of the slide for viewing
Continued… • Coarse adjustment knob: • Large movements of the stage • Fine adjustment knob: • Precise focusing under High power
Continued… • Diaphragm: • regulates the amount of light passing through the slide
Continued… • Illuminator • Light source • Base: • provides support for microscope
Continued… • Body tube: • Connects Ocular to Nosepiece
Field of View • Field of View (FV) is the illuminated circle that you see when looking through the ocular eyepiece. • If we know the diameter of the FV then we can estimate the size of our microorganisms.
Field of View • With our microscopes the diameter of the FV under low power is 4 mm • FV is measured in micrometers or microns. • 1 mm = 1000 microns • Therefore, our FV under low power is 4000 microns
Using the Field of View to Estimate Microscopic Measurements If an organism takes up ½ of the FV under low power, it must be about 2000 microns in length