💡 Lumière

🕶️Brewster's Angle Calculator Calculate the angle at which reflected light is fully polarized, free online. 🔦Candela ⇄ Lumen Converter Convert luminous intensity in candela to luminous flux in lumens (and back) for a given beam angle, free online. 🌡️Colour Temperature (Kelvin → RGB) Calculator Convert a colour temperature in kelvin to an approximate RGB and hex colour, mired value and lighting description, free online. 🔮Critical Angle Calculator Calculate the critical angle for total internal reflection, free online. 🌈Diffraction Grating Calculator Find the diffraction angles and the maximum order of a grating from its line density and the light's wavelength, free online. 📸F-Stop & Aperture Calculator Find the aperture diameter for a focal length and f-number, and the light difference in stops between two f-numbers, free online. 🪟Fresnel Equations (Reflectance) Calculator Calculate how much light is reflected and transmitted at the boundary between two media for s, p and unpolarised light, free online. 🕯️Illuminance from a Point Source Calculator Calculate illuminance in lux and foot-candles at a distance from a lamp using the inverse square law, free online. 🔎Lens Magnification Calculator Calculate magnification and image height for a lens, free online. 🔎Lens Maker's Equation Calculator Calculate the focal length of a lens from its refractive index and surface radii, free online. 👓Lens Power (Diopters) Calculator Convert between lens focal length and optical power in diopters, free online. 🌟Light Travel Time Calculator Calculate how long light takes to travel a distance, free online. 🌈Light Wavelength to Frequency Calculator Convert light wavelength to frequency and photon energy, free online. 💡Lumens to Watts Converter Convert luminous flux in lumens to electrical power in watts, free online. 💡Luminous Efficacy of a Lamp Calculator Compare lamps by lumens per watt and efficiency relative to the theoretical maximum of 683 lm/W, free online. 💡Lux to Foot-candle Converter Convert illuminance between lux and foot-candles, free online. 🕶️Malus's Law (Polarisers) Calculator Calculate the light intensity transmitted through one or two polarising filters at a given angle, free online. 🔬Optical Density Calculator Convert between transmittance and optical density (absorbance), free online. 🔭Rayleigh Criterion (Resolution) Calculator Find the smallest angle and separation a telescope, camera lens or eye can resolve from its aperture and wavelength, free online. 🔍Snell's Law Calculator Calculate the refraction angle of light passing between two media using Snell's Law, free online. ☀️Solar Irradiance on a Tilted Surface Calculator Calculate the sunlight power hitting a tilted solar panel or window from the sun's position and the surface orientation, free online. 🔬Thin Lens Equation Calculator Calculate image distance and magnification from focal length and object distance, free online.