4. • This is a compound
light microscope.
• It is called this because
it has two or more
lenses (the eyepiece
lenses and the objective Mechanism for enlarging
lenses), and makes use an image
of light to produce an
image.
5. Maintains
proper distance Eyepiece
between lenses
Magnification
Body Tube
Revolving Nosepiece
Hold objective
rotates to change
magnification Arm
Magnification Objectives Supports body tube
Holds slide Stage Clips Stage Supports slide
In place
Coarse Focus
Regulates
Diaphragm Focuses image
amount of light Fine Focus
Light source Sharpens the image
Reflects light
towards eyepiece Base
Supports microscope
6. the specimen
the image
the eye
Each lens magnifies the
image, increasing its
overall size
A lens is a bi-convex disk that bends light
The bent rays produces an image
The farther the light rays are bent, the larger
the image appears
7. the specimen
the image
the eye
As the light rays are spread
Resolving power: A measure of farther apart, the clarity or
the ability of a
lens or optical system to form
resolution of the image
separate and decreases
distinct images of two objects
with small Light microscopes are limited in their
angular separation. magnification by their resolving power!
8.
9. the specimen
the image
the eye
The image is always seen upside
down and backwards from its
actual position
10. The magnification
• Place the Slide on the of the eyepiece is
Microscope 10 times (10x)
• Use Stage Clips to hold slide
in place
• Open the diaphragm (shutter)
and switch on the lamp power
• A microscope has several lens
and each magnifies the
specimen like a magnifying
glass
11. •The two lenses are called:
– Ey
epi
ec
e
– Ob
jec
tiv
e
•The eyepiece has a magnification of “10x”
•The magnification of the objective lenses vary
400
13. •Always start with the low
power objective (4X)
•Always focus using the
coarse knob, then the fine
focus knob.
•Centralise what you want
further magnified
•Switch to the 10X
objective lens and if
needed, to the 40X
objective lens
14. • Follow steps to focus
using low power
• At high power, use only
the fine focus knob!
• Click the nosepiece to the
longest objective
• Do NOT use the coarse
focusing knob as it will
crack the slide.
• Use the fine focus knob to
bring the slide
15. • Do NOT remove the slide as it is very
close to the objective lens.
• To remove slide, switch to low-power or
mid-power objective lens.
What will you find?
16. Let’s Review! 9. Eyepiece
1. Body tube
2. Nosepiece
10. Arm
3. Low power
4. Medium power
11. Stage
5. High power
6. Stage clips 12. Course adjustment
7. Diaphragm 13. Fine adjustment
8. Light source
14. Base
17. • Always carry with 2 hands – one hand on
the arm, the other on the base
• Only use lens paper for cleaning
• Do not force knobs
• Always store covered
• Keep desk clear of objects and cords
Notas del editor
Students will have their microscopes out, for reference as we go through each of the steps. As an introduction, students will be asked what kinds of things they can do with this tool.
Teacher demonstrates how to hold the microscope, where the lens paper is located and how to use it. Students will be invited to turn the knobs and observe the stage as it moves up and down. Teacher will demonstrate how to store the microscope.
Teacher demonstrates how to hold the microscope, where the lens paper is located and how to use it. Students will be invited to turn the knobs and observe the stage as it moves up and down. Teacher will demonstrate how to store the microscope.
This is the exact version of the microscope used in class. Students will be identifying the parts on the microscopes at their desks as we go along and what their functions are.
Give students a slide from the “common things” set, each student will practice focusing and changing objectives.
Have students exchange slides so they can look at different things, walk them through using the high power objective to focus slides. Emphasize not using the coarse objective during this process, as it will crack the slides.
Teacher demonstrates how to hold the microscope, where the lens paper is located and how to use it. Students will be invited to turn the knobs and observe the stage as it moves up and down. Teacher will demonstrate how to store the microscope.