Microscope: Developments in Imaging Technology

Question 1

Who created the first microscope in teh 1500’s?

Answer 1

Hans and Zacharias Janssen, Dutch lensmakers.

Question 2

The Janssen Compound Microscope was a “compound” microscope because…

Answer 2

It used more than 1 lens. It ws a two-lens system of and eyepiece(ocular lens) and an objective lens.

Question 3

What was the magification of the first microscope and why was that signifigant?

Answer 3

It’s maginifcation was 20x and was significant becuase it extended the reach of the human eye.

Question 4

What kind of of microscope did Englishman Robert Hooke develop and in what year?

Answer 4

Hooke made a 3 lens microscope in 1665

Question 5

What did Hooke study and illustrate?

Answer 5

Hooke studied ‘microscopic’ organisms. He made a book with drawings of what he saw throught the microscope.

Question 6

What term is Hooke credited with using and what did it describe?

Answer 6

He was credited with using the term “cell” to describe empty chambers he observed in cork.

Question 7

What did Anton van Leeuwenhoek, a Dutch businessman devleop?

Answer 7

He developed a lenses that allowed for greater magification up to 250X

Question 8

What did van Leeuwenhoek see for the first time with this magnification?

Answer 8

He was the first to see the movement of singlel-celled organisms as small as bacteria.

Question 9

What is the eye piece or Occular Lens?

Compound Microscope

Answer 9

magnifies the image produced by the objective lens (10X)

Question 10

Coarse Focus or Adjustment Knob

Compound Microscope

Answer 10

allows for intital or large changes in focus

Question 11

Fine Focus or Adjustement Knob

Compound Microscope

Answer 11

allows for final or small changes in focus

Question 12

Revolving Nose piece

Compound Microscope

Answer 12

allows one to change the objective lens used

Question 13

Objective Lenses

Compound Microscope

Answer 13

provide various levels of magnification of the speciment

Question 14

Stage

Compound Microscope

Answer 14

holds the slide/specimen

Question 15

Stage Clips

Compound Microscope

Answer 15

holds the slide in place

Question 16

Diaphragm

Compound Microscope

Answer 16

allosw for control of how much light passes through the speciment

Question 17

Light Source

Compound Microscope

Answer 17

provides light necessary to illuminate the specimen

Question 18

Arm

Compound Microscope

Answer 18

holds the lenses the proper distance from the specimen

Question 19

Base

Compound Microscope

Answer 19

provides support for the parts of the microscope

Question 20

Total Magnification Formula

Answer 20

Total Magnification =
(eyepiece) (objective)
Low: (10)(4)= 40x,
Medium (10)(10)=100x,
High (10)(40)=400x

Low: (10)(4)= 40x, Medium (10)(10)=100x, High (10)(40)=400x

Question 21

What is the Magnification Equation

Answer 21

h i
M = ——-
ho
Magnification can be calculated by taking a dimension of the image such as height and dividing it by the same dimension of the object.
example: calculate the magnification power of a microscope if a 1.4 mm long speciment (object=0) appears to have a length of 46.3 mm(image=i)
33x

Question 22

What is field of View (FOV)

Answer 22

the entire area that you see when you look htrough a microscope

You can use a ruler under the microscope to measure the diameter of the

Question 23

How do you calculate the Field of View?

Answer 23

MHFH=MLFL

M= magnification, H= high power F=field of view L=low power

due to the small size of the field of view, sometimes the unit micrometer is used. 1mm = 1000 um