Table 7 Technical specifications of prevalent computer screens and calculation of the minimum and maximum displayable aliased text size (logMAR) for a viewing distance of 40 cm
Screen specifications | logMAR at 40 cm | ||||||
|---|---|---|---|---|---|---|---|
Resolution | Diagonal (inch) | pixels | size (cm) | pixel size (mm) | ppi | Min | Max |
FHD | 15.6 | 1920 × 1080 | 34.54 × 19.42 | 0.18 | 141.26 | 0.2 | > 1.3 |
FHD | 14 | 1920 × 1080 | 30.99 × 17.43 | 0.16 | 157.38 | 0.2 | > 1.3 |
4 K | 15.6 | 3840 × 2160 | 34.54 × 19.42 | 0.09 | 282.4 | −0.1 | > 1.3 |
4 K | 14 | 3840 × 2160 | 30.99 × 17.43 | 0.081 | 314.7 | < −0.1 | > 1.3 |
4 K | 13.3 | 3840 × 2160 | 29.44 × 16.56 | 0.08 | 331.3 | < −0.1 | > 1.3 |
2.5 K | 10 | 2560 × 1440 | 22.14 × 12.45 | 0.09 | 293.78 | −0.1 | 1.3 |