Design Nomenclature / Color
Purkinje shift
Also called Purkinje effect, scotopic shift
- Color
- Light & Optics
- 2D & 3D
This entry has not been translated yet and is shown in English.
As light falls and vision hands over from cones to rods, peak sensitivity moves from about 555 nm to 505 nm. Reds darken toward black and blues hold their luminance — which is why a red geranium that outshone the foliage at noon goes flat and dead at dusk while the leaves stay legible.
In practice
The practical case is dark interfaces and night instrumentation: red on a dark ground loses more apparent luminance in dim viewing than its measured contrast ratio predicts.