Lab 2 Flashcards
Which lens does the user look through on a microscope?
Ocular lens
Which lens is used to set various magnifications?
Objective lens
Which lens typically is 10x or 15x?
Ocular
Which lens has the most varied possible magnification lenses?
Objective
Total magnification =
Ocular zoom x Objective zoom
If the ocular lens is 10x and the objective lens is set to 4x, what is the total magnification?
40x
If the ocular lens is 10x and the objective lens is set to 100x, what is the total magnification?
1000x
If the ocular lens is 10x and the objective lens is set to 40x, what is the total magnification?
400x
What part of the microscope holds the specimen in place?
Specimen stage and clips
What purpose does the stage mover serve on the microscope?
To adjust the stage left/right or forward/backward
Why would you use the stage mover?
To center the subject in the field of view
How is the nosepiece on the microscope used?
Rotate to choose the desired objective lens
What is the light source for a compound microscope?
Light bulb
What is the Rheostat used for?
To set a brightness for the bulb
What is the Condenser Diaphragm used for?
To control the amount of light entering the objective lens.
If you look through the ocular lens and don’t see anything, what items would you check?
- power switch - plug (at outlet and at microscope) - rheostat setting - condenser diaphragm is open - objective lens is locked in place - slide position - if outlet is dead
At which settings are you permitted to use both course and fine adjustment knobs?
4x and 10x
At which settings are you use only fine adjustment knobs? Why?
40x and 100x. Using the course adjustment could push the objective lens through the slide.
After a slide is in place on the stage, what is used to center the image?
The stage mover knobs
As you zoom in the microscope, would you need to increase or decrease the amount of light?
Increase
As you zoom out the microscope, which you need to increase or decrease the amount of light?
Decrease
A microscope’s usefulness depends mainly on what two things?
Magnification and Resolution Power
The minimum distance between two points at which those points can still be seen as different objects refers to what microscope feature?
Resolution Power
What does resolution power provide?
Greater image detail
High zoom + low resolution results in
Narrow field of view with blurry to no detail image
Low zoom + high resolution results in
Wide field of view with sharp image
High zoom + high resolution results in
Narrow field of view with sharp, detailed image
What is seen through the ocular lens is called…
the field of view
If the subject is upside down and inverted, what is the problem?
The subject was placed on the stage upside down.
T or F: Specimen size is the same as field of view diameter.
False
If you move the stage right, the image will move…
Left
The distance between the nearest and farthest objects that remain in focus is called…
Depth of field
When zoom increases, field of view
Decreases
When zoom decreases, field of view
Increases
If the specimen has disappeared from the field of view, what has happened?
Zoom has increased
Why do we center the image each time the zoom is changed?
To make sure it remains in field of view as zoom settings increase
The field of view is measured in
mm
To determine the width of the field of view, we measure its
Diameter
When we have an original diameter and magnification settings and are provided either one new diameter or magnification setting, what is the formula to figure out the missing diameter or magnification setting?
D1M1 = D2M2
D1M1 = D2M2
What is the formula to solve for D2?
D2 = D1M1 / M2
D1M1 = D2M2
What is the formula to solve for M2?
M2 = D1M1 / D2
A light microscope that uses multiple lenses for magnification is called a…
Compound microscope
What is the field of view?
What the observer sees when they look through the ocular lens.
What happens if you use a t-shirt or kleenex to clean the microscope lenses?
It will scratch them
