Radiant intensity is a measure of the power emitted, transmitted, or received per unit solid angle. It quantifies the amount of radiant energy that is emitted or transmitted in a specific direction from a source.

Common examples of related units of measurements include radiant flux, radiant exitance, and radiant emittance. Radiant flux measures the total amount of radiant energy emitted by a source, radiant exitance measures the radiant flux per unit area of a surface, and radiant emittance measures the radiative power emitted from a surface per unit area.

• Radiant intensity is crucial in various fields such as astronomy, optics, and lighting design.
• It helps in determining the brightness and efficiency of light sources.
• Radiant intensity is essential in calculating the radiant heat transfer between surfaces.
• It plays a key role in characterizing the performance of optical devices and systems.