420 nm to RGB & Color Calculator
Approximate how 420 nm monochromatic spectral light can be represented in sRGB, and calculate CIE 1931 tristimulus values, THz frequency, and photon energy.
Why You See This Color (420 nm)
At 420 nm, monochromatic light stimulates human Short-wavelength (S) retinal cone photoreceptors with minimal activation of Medium (M) and Long (L) cones. The brain interprets this high-frequency electromagnetic stimulus (approximately 713.792 THz, carrying 2.952 eV per quantum photon) as deep violet. Because the eye's photopic luminous efficiency V(λ) drops sharply toward the near-ultraviolet threshold, this wavelength requires greater radiant flux to match the perceived brightness of green light.
Physical Parameter Breakdown
Physics Teacher & Educational Technologist • Brăila, Romania
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