posted by mina .
An American standard analog television picture (non-HDTV), also known as NTSC, is composed of approximately 485 horizontal lines of varying light intensity. Assume your ability to resolve the lines is limited only by the Rayleigh criterion, the pupils of your eyes are 4.80 mm in diameter, and the average wavelength of the light coming from the screen is 570 nm. Calculate the ratio of the minimum viewing distance to the vertical dimension of the picture such that you will not be able to resolve the lines.
1.22*(lambda)/D = (H/480)/L
H is the screen height.
L is the viewing distance for which the line width on the screen equals the eye's limit of resolution.
D = eye pupil diameter.
lambda = avg. wavelength = 570*10^-9 m
Solve for the desired L/H