User:The Ergonomist/sandbox

Optimal viewing distance
"The optimal viewing distance" is based on the limits of the human eye, i.e. its angle of resolution. This is its ability to distinguish between two pixels. For normal visual acuity (6/6 vision), this angle is 1 arcmin. To obtain a fixed distance for a given resolution, it must be expressed in picture heights (H). If a screen is 50 cm high and it is at a distance of 250 cm, then in picture heights, its distance is 5 H ($250⁄50$). Mathematically, this gives the distances shown in the following table: This table can be used in a number of ways :


 * Find the optimal distance for a given screen. Example: for a 4K UHD screen 140 cm high (112 inches diagonal), the optimal distance is 140 × 1.6 = 224 cm.
 * Find the right screen size. Example: for a 1080 HDTV used at a distance of 250 cm, you need to find a screen whose height is close to $250⁄3.2$ = 78 cm (63 inches diagonally).
 * Find the right video resolution. Example: a 53 cm high screen (43 inches diagonal), located at a distance of 300 cm, does not need to show video with a resolution higher than HD 720. Presenting a higher resolution means a larger ecological footprint with no perceptible gain.
 * Find the best seat in the cinema. DCI 4K cinema has the same number of lines as 4K UHD (the DCI 4K format is wider). The optimal distance is therefore 1.6 times the height of the screen. The best compromise with the ideal listening zone, the sweet spot, must be found; "Sound is 50 percent of the movie going experience" - George Lucas.

Please note! The optimal viewing distance is not suitable for designing a user interface; It is the distance actually observed in households that should be used. It is much greater than the optimal viewing distance and highly variable.