Digital Imaging

Question 0

What is CCD?

Answer 0

Charged-coupled device

Question 1

What is SLR?

Answer 1

Single lens reflex

Question 2

What is a capacitor?

Answer 2

A capacitor is made of any two conductors that are kept separated. They are usually two metal plates held parallel and separated by vacuum or another material known as dialectrine.

Question 3

What is the amount of charge stored on a capacitor?

Answer 3

The amount of charge (q) stored on a capacitor is proportional to the voltage (v) applied. The constant of proportionality is known as the capacitance (c).

Question 4

Charge=?

Answer 4

Charge = capacitance x voltage

Q (coulombs) - C (Farads) - V (Volts)

Question 5

What is frequently used in magnification?

Answer 5

CCDs are frequently used as the image sensor.

Question 6

Linear magnification =

Answer 6

Linear magnification = Image height/object height

= I/O

Question 7

What is linear magnification?

Answer 7

It is defined as the length of the image on the CCD divided by the length of the object.

Question 8

Resolution in a CCD

Answer 8

A CCD just resolves two closely spaced points on the object if the images of these points are separated by at least a distance equal to 2 Pixar lengths.

Question 9

Quantum efficiency (QE)

Answer 9

The ratio of the number of electrons enjoyed to the number of incident photons. A high QE means you can acquire the image in less time.

Question 10

Uses of CCDs?

Answer 10

Digital cameras
Video recorders
Endoscopy
X-ray detectors

Question 11

Advantages of CCD images over those on films?

Answer 11

• Image is digital and so can manipulated/stored/transmitted with a computer.
• The quantum efficiency is high so fainter images can be recorded in less time.
• The response is uniform over a wide range of wavelengths.
• Faint as well as bright objects can both be seen clearly in the same image.