Future Lighting Solutions, a division of Future Electronics Inc., has unveiled the Usable Light Tool, an online resource that enables lighting designers to model and evaluate power LED performance for lighting in real-world environments. In the past, the analysis of LEDs had been limited by the assumption of a junction of 25 °C, which yielded incomplete and inaccurate results. Taking into account the effects of relationships among dissipated power, heat, light output, current and forward voltage, the tool enables users to select LEDs and modify parameters such as the number of LEDs, the ambient temperature and the thermal resistance of the system. It also provides details on the usable light and efficiencies that can be expected when using the specifications.