Week 3: Microscopes

Question 1

Occular Lens

Answer 1

Also known as the eyepiece. This is the part used to look through the microscope. Its found at the top of the microscope. Its standard magnification is 10x

Question 2

Objective Lens

Answer 2

Magnification lenses. Typically a light microscope has four of these lenses: 4X, 10X, 40X, and 100 x.

Question 3

4X Lens Name

Answer 3

Scanning Objective

Question 4

10X Lens Name

Answer 4

Low Power Objective

Question 5

40X Lens Name

Answer 5

High Power Objective

Question 6

100X Lens Name

Answer 6

Oil Immersion Lens .. Oil Immersion must always be used with this lens

Question 7

Specimen Stage & Clips

Answer 7

Platform

Question 8

Stage Mover

Answer 8

Moves the stage left and right AND front to back

Question 9

Nosepiece

Answer 9

also known as the revolving turret. It holds the objective lenses. It is movable hence it cal revolve the objective lenses depending on the magnification power of the lens.

Question 10

Head

Answer 10

Holds the optical parts in the upper part of the microscope

Question 11

Base

Answer 11

Acts as the microscope’s support

Question 12

Arm

Answer 12

Connects from the base and to the head. It gives support to the head of the microscope and it is also used when carrying the microscope.

Question 13

The Adjustment knobs

Answer 13

These are knobs that are used to focus the microscope. There are two types of adjustment knobs i.e fine adjustment knobs and coarse adjustment knobs.

Question 14

Course Adjustment Knob

Answer 14

Moves the stage up or down for focusing changes

Question 15

Fine Adjustment Knob

Answer 15

Slightly moves the stage up or down for minor focusing changes that sharpen the image

Question 16

Diaphragm

Answer 16

It’s also known as the iris. Its found under the stage of the microscope and its primary role is to control the amount of light that reaches the specimen.

Question 17

Rheostat

Answer 17

Brightness Adjustment

Question 18

Microscope Illuminator/ Light Source

Answer 18

This is the microscopes light source, located at the base.

Question 19

Condenser

Answer 19

These are lenses that are used to collect and focus light from the illuminator into the specimen (you can manipulate its direction and angles of reflection). They are found under the stage next to the diaphragm of the microscope.

-They play a major role in ensuring clear sharp images are produced with a high magnification of 400X and above. The higher the magnification of the condenser, the more the image clarity. More sophisticated microscopes come with an Abbe condenser that has a high magnification of about 1000X.

Question 20

Total Magnification

Answer 20

Product of ocular lens magnification AND objective lens magnification

Question 21

Low power lens require what light ?

Answer 21

Less light

Question 22

High power lens require what light ?

Answer 22

More light

Question 23

Course vs Fine Adjustment Knob usage

Answer 23

Course Adjustment: 4 - 10 X
Fine Adjustment: 40-100 X

Never use course adjustment with 40 or 100 x because you may accidentally push objective into slide

Question 24

Resolving Power

Answer 24

Measure of the ability to distinguish between two objects that are close together. It is the minimum distance between two points at which those points can still be seen as different objects

The greater the resolving power, the more detail and clarity you can actually see.

Question 25

Depth of field

Answer 25

how far above and below the sample plane the objective lens and the specimen can be while remaining in perfect focus.

Question 26

Types of microscopes

Answer 26

1. Simple Microscope- can see difference in shapes between RBC
2. Compound- - two lenses provide more magnification power
3. Stereo (dissecting)- low magnification but used for larger images and can provide 3D view
4. Confocal- uses laser light- offer higher degree of magnification.
5. Scanning Electron Microscope (SEM)- uses electrons rather than light for image formation. Allows for control over magnification. Also views 3D images
6. Transmission Electron Microscope (TEM)- uses electrons in creating a magnified image but with 2D images. Good for viewing objects with some degree of transparency.

Question 27

Depth of field vs field of view

Answer 27

Depth of field refers to the ability to view details of an object with a certain thickness. Higher magnifications may limit the ability to see details of the specimen in focus due to the thickness

Field of view is a similar concept but it’s the circular area you see when looking through the eyepiece of the microscope.