Question

2) (Diffraction limit of human eye) (Adapted from a problem by Prof. Walter Smith.) Let's see how the resolution limit for the human eye due to diffraction from a circular aperture (the pupil) compares to that required to see things on computer screens and high-def TVs. Assume that the wavelength of light is 550 nm on average, and that the pupil of the eye has a diameter of 4.00 mm. a) How does the angle subtended by a single picture element (pixel) on a laptop screen compare to the minimum angle resolvable by the human eye? Compute both values and compare quantitatively. Assume a laptop screen is about 13 inches wide and that there are about 1000 pixels across and that you sit a distance 2.50 feet away from it. b) How does the angle subtended by a single picture element (pixel) on a big HD TV compare to the minimum angle resolvable by the human eye? Assume the TV screen is about 1.40 m wide and about 2000 pixels across, and that you are chilling out about 3.00 m away.

Answer 1

jesolvable by minimum human angle Rye - 1.224 ra rection radian 10 22 X 550X10 radiam o 5 4x103 4 10677 X 10' radian · o & Leptop screen angle gle on substanded by eye. 13x0.0254 - 1000 0.3048 2.5 x jadian . 4.33 X10l o = screen Pikel minimum of laptop resolvable angle sublended by is large than angle. so the pixel look continuous pixel. 2 will not (we can too see the

1.4 Я во 3 o = 2.33 xlo radian - angle larger subtended than by Ho Tv is minimum resolvable angle In this case also screen will look dis continuous