The human eye has an approximate angular resolution of ɸ = 5.8 x 10-4 rad and a typical photo printer prints a minimum of 300 dpi (dots per inch, 1 inch = 2.54 cm).

The human eye has an approximate angular resolution of ɸ = 5.8 x 10-4 rad and a typical photo printer prints a minimum of 300 dpi (dots per inch 1 inch = 2.54 cm). At what minimal distance z should a printed page be held so that one does not see the individual dots.

It is given, angular resolution of human eye ɸ = 5.8 x 10,-4, rad and printer prints 300 dots per inch. ,It is given, angular resolution of human eye ɸ = 5.8 × 10,-4, rad and printer prints 300 dots per inch.,the linear distance between two dots is l = 2.54/300 cm = 0.84 × 10,-2, cm.,At a distance of z cm, this subtends an angle ,ɸ = l/z,z = 1/ɸ = (0.84 × 10,-2, cm)/(5.8 × 10,-4, )= 14.5 cm ,if a printed page be held at a distance 14.5 cm ,then one does not be able to see the individual dots.