1. Important Microscope Techniques
Field of view
the area you can see on the slide
as magnification increases field of view
decreases
Depth of field
thickness of the zone that is in focus.
as magnification increases depth of field decreases

2. What happens to the field of view as magnification increases?

3. Example of Depth of Field
                                                               
Euastrum verrucosum

4. Brightness decreases Orientation
as magnification increases, brightness
decreases
Orientation
position of the image
compound microscopes flips image upside
down and left to right

5. Working Distance objective lens and the area in focus
the distance between the tip of the
objective lens and the area in focus
as magnification increases, working
distance decreases!

6. Focusing
At low power, use coarse adjustment first, then use fine adjustment
Focus at low before switching to high power because:
1. object will be in approximate focus at high
2. you won’t hit high power lens on slide
At high power never use coarse adjustment because:
you could damage objective or slide
Use fine adjustment at high power to see different levels within the same cell

7. Centering to center an object, move the slide:
in the opposite direction that you want the image to move in
always center at low before switching to high power because:
-if you don’t the object will not be within high power field of view

8. In order to center this object, in what direction should you move the slide?

9. Preparing a “wet mount” slide
Place a drop or two of water on empty slide
Add cells you want to look at
Add some more water
Cover cells with a “cover slip”
To avoid trapping air bubbles….
add cover slip at 45 degree angle, then slowly lower the upper edge

10. Wet Mount Image What do you notice about the angle?
Why is this important?

12. Eyepiece – Magnifies the image. Part that you look through.
Body Tube – Refracts (directs) light towards the eyepiece.
Coarse Adjustment Knob – Moves the stage, allowing the image to focus.
Fine Adjustment Knob – Changes depth of field (near sighted vs. far sighted), makes image sharper
Arm – Supports the upper pieces of the microscope
Base – Supports the entire microscope
Light Source – Provides light to make specimen visible
Diaphragm – Filters the light (either amount of light or color)
Stage – Platform that holds the slide
Stage Clips – Keeps the slide in place
Low Power Objective Lens – Magnifies the image
High Power Objective Lens – Greatly magnifies the image
Nosepiece – Rotates the Objective lens, allowing you to switch between high and low power
Slide – Glass that contains specimen. It is placed on the stage so that light passes through it

13. Magnification
When trying to figure out what magnification you are currently viewing the slide at, multiply the magnification of the Eyepiece by the magnification of the objective lens.
Ex: If the Eyepiece magnifies the image by 10x, the low power objective lens magnifies it by 4x, and the high power magnifies it by 10x…
-The total magnification under low power would be 40x
-The total magnification under high power would be 100x