Recent advances and perspectives in photometry in the era of LED lighting

Photometry contributes to our understanding how the world is perceived by the human visual system, where a specific example is an early study of photographic plates. Nowadays photometry has an important role in measurement of lighting, particularly in the transition from incandescent lighting to LED lighting. In the context of sustainability and energy efficiency, updated photometric methods are needed that address the spectral, color, geometrical, and temporal characteristics of LED light sources. Highlights of the recent advances in these measurement methods are reviewed. Furthermore, challenges and achievements are described in the measurement of optical power, particularly related to the definition of the photometric SI base unit, the candela. These achievements are based on progress in the development of underpinning optical measurement standards, with a focus on technologies like the electrical substitution radiometer and the predictable quantum efficient detector. As a conclusion, the importance of ongoing research and development in photometry is emphasized considering its crucial role in supporting the advances of LED lighting technology and sustainable development goals of lighting industry.