Light & Optics Silo380 nm – 750 nm400 THz – 790 THz
Light Lab
Electromagnetic spectrum calculators built on the CIE 1931 2° Standard Observer, standard sRGB colorimetry (IEC 61966-2-1), and quantum photon energy relations (E = h · f).
371 Pages
Wavelength to RGB
Convert any visible wavelength (380–750nm) into exact sRGB values, CIE XYZ tristimulus coordinates, THz frequency, and eV photon energy.
sRGB Gamma
HEX to Linear RGB & XYZ
Decompand non-linear sRGB gammas (γ ≈ 2.2) into physical photon irradiance, HSL components, and dominant spectral wavelength.
WCAG 2.1
WCAG Contrast Checker
Verify relative photometric luminance ratios (1:1 to 21:1) against W3C AA and AAA accessibility requirements with live visual preview.
Physical Reference Wavelengths
NIST & Laser Emission Standards405 nm
Violet Laser
Near-UV Semiconductor
740.228 THz3.061 eV
445 nm
Royal Blue
High-Energy Blue LED
673.691 THz2.786 eV
488 nm
Cyan / Aqua
Argon-Ion Laser Line
614.329 THz2.541 eV
520 nm
Pure Green
Direct Diode Laser
576.524 THz2.384 eV
555 nm
Peak Photopic
Human Eye Maximum Sensitivity
540.167 THz2.234 eV
589 nm
Sodium D-Line
Street Lamp Emission
508.985 THz2.105 eV
633 nm
HeNe Laser Red
Standard Helium-Neon Line
473.606 THz1.959 eV
680 nm
Deep Red
Chlorophyll-A Absorption
440.871 THz1.823 eV
Spectral Wavelength Index (380 nm – 750 nm)
Quickly browse every integer wavelength in the visible light spectrum:
380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750