1 What Limits Diffraction

Question 1

What three things limit vision?

Answer 1

Diffraction

Aberrations

Cone spacing

Question 2

When given a PSF, the larger one will correspond to a ______ pupil!

Answer 2

Smallllll

Question 3

(TP) better vision is achieved with …

A) with more confined PSF
B) with less confined PSF
C) PSF size doesn’t matter

Answer 3

A) with a more confined PSF

Question 4

(TP) If we consider DIFFRACTION only, better vision is achieved with…

A) smaller pupil
B) larger pupil

Answer 4

larger pupil

Question 5

Larger aperture, means _______ aberrations

Answer 5

Worse

Question 6

What is the ‘sweet spot’ for diffraction + aberrations?

Answer 6

Between 2-3mm pupil size… about 1 arcmin

Question 7

For the Retina display, what’s the pixel density?

What’s the suggested viewing distance? What size devices have more pixels?

Answer 7

326 PPI

12inches for 326 PPI. Smaller devices are better because the larger devices are usually further from the eye

Question 8

Average number of cones in the fovea expressed in um and arcmin?

Otherwise called the digital sampling limit to vision

Answer 8

2.6um=0.5 arcmin

Question 9

(TP) With half the photo sensor pixel size, resolution is…

Double

Half

Same

Answer 9

Double!

Question 10

For every 5 arcmin, you pass over about __cone receptors

Answer 10

10

Question 11

For pinhole visual acuity, a smaller pupil results in a _______ depth of focus?

Answer 11

Larger

Question 12

A small pinhole:

______ the effects of aberrations

______ the range of acceptable vision (depth of focus)

_______ in the size of circle of least confusion

Diffraction effects contribute to an ______ of the size of circle of least confusion

Answer 12

Reduces

Increases

Increases

Increases