Physics Of Light Research Focus Lecture 2

Question 1

What did Newton find about light?

Answer 1

Light can be decomposed into different wave lengths so different coloured light comes out when it hits a prism.
The prism defracts the white light which is a combination of different wave lengths.

Question 2

How much of the electromagnetic spectrum can our receptors in the retina pick up?

Answer 2

400nm (blue) to 700 (red) nm in wavelength (visible light)

Question 3

Is colour important for us?

Answer 3

Yes it helps us identify objects in the physical world.

Question 4

What is achromatic components important for?

Answer 4

Spatial detail

Question 5

What is chromatic components important for?

Answer 5

Colour

Question 6

How do we see colour?

Answer 6

Light is projected into the retina and specific respectors (cones) respond and are sensitive to certain wavelengths (colours).

Question 7

What are rods and what function dot hey do?

Answer 7

Photoreceptors that give us achromatic vision such as night vision and there is only 1 type

Not good for resolving spatial detail, therefore at night there is not high visual acuity

Question 8

What are cones and what is there function?

Answer 8

They are photoreceptors and three are three types

They give us daytime, chromatic and achromatic vision

Question 9

What are the three types of cones?

Answer 9

L cones respond to long wavelengths (red)

M cones respond to middle wavelengths (green)

S cones respond to short wave lengths (blue)

Question 10

Describe the distribution of rods and cones?

Answer 10

Cones are in the middle of the fovea.

Rods density is higher nearer to the middle of the fovea but are distributed more than cones across the retina.

Question 11

Where in the retina is it rod free?

Answer 11

Central fovea

Question 12

Where in the retina is it fovea and S cone free?

Answer 12

Very central fovea.

Question 13

How can we see specific colours?

Answer 13

Mixture of wavelengths such as green wavelength and red wavelength to make yellow

Or

Just a yellow wavelength

-Both physically different in the physical electromagnetic world but both appear identical

Question 14

How can we see different colours other than blue green and red?

Answer 14

We have univariant cones

Each cone is more sensitive to other photons and electromagnetic waves

Whichever cone is being stimulated more than the other that colour will be encoded such as green and red cones being stimulated more will encode the yellow colour.

Question 15

What is vision being trichromatic?

Answer 15

Vision is three dimensional