Advancing the effective use of light for society and the environment.

Vol. 1, No. 2

Wednesday, July 3, 2002

General News
LRC Unveils New Solid-State Lighting Web Site
Solid State Lighting

The LRC's solid-state lighting Web site has a new look and feel, and it's easy to use. It features research projects, resources, educational opportunities, and links about LEDs and other solid-state lighting technologies.

Using the LRC's multidisciplinary strength, the Solid-State Lighting Program is bringing scientists and engineers from diverse disciplines together to examine all aspects of solid-state lighting from system development to applications that will eventually change the way we light our world (see next story).


Three-Year Project Focuses on High Efficiency Solid-State Lighting
LED Testing

LRC scientists are working in collaboration with the University of California at Santa Barbara (UCSB) to develop a highly efficient solid-state lighting system for general illumination. The project is funded by a cooperative agreement from the U.S. Department of Energy.

The LRC team is focusing on defining specifications for the new light source, developing suitable epoxy materials to encapsulate the new semiconductor element, and integrating the device with optics and electronic controls to develop novel lighting fixtures that may someday revolutionize the way we light our homes, offices, stores, and other buildings. Click here to learn more.


LRC Develops Retinal Flux Density Meter
New device could lead to improved safety and energy efficiency standards

Scientists at the Lighting Research Center (LRC) have designed and constructed a retinal flux density (RFD) meter. One reason lighting designers and practitioners most commonly use illuminance as a performance metric is that illuminance meters are easy to use and relatively inexpensive. Unfortunately, under certain conditions (such as under mesopic light levels) these meters don't accurately represent the human response to lighting. The LRC developed
RFD Meter

the RFD meter to address this issue. It can serve as a standard illuminance meter, or it can measure flux density on the retina using both photopic and scotopic spectral responses. This dual measurement ability allows the instrument to determine standard illuminances and RFDs at mesopic levels.

Although the prototype device is not yet commercially available, a commercial instrument that provides accurate measurements at photopic, scotopic, and mesopic light levels could be manufactured for less than $1000. Researchers and practitioners could use such device to assess the utility of moving beyond static photopic illuminance levels. Widespread use of these devices might lead to new standards that would improve both energy efficiency and safety. Click here PDF Icon to learn more about the RFD meter.


New Lighting Answers Will Shed Light on T5 Fluorescent Systems

The latest in the Lighting Answers series, Lighting Answers: T5 Fluorescent Systems, will be launched online August 1, 2002, and will answer commonly asked questions about the new T5 fluorescent lamp technology. The report will cover physical characteristics, economic issues, and design and application issues related to T5 lamps. Lighting Research Center researcher Yukio Akashi will answer questions and offer solutions to problems facing lighting practitioners who may wish to use the new T5 lamps.

This document will be available both online to allow readers to access the questions and answers in any order, and in a printer-friendly version. It will include several case studies based on the Lighting Research Center's extensive experience in product testing. Watch for Lighting Answers: T5 Fluorescent Systems at in August.


"Phototransduction for Human Melatonin Suppression" Published

This peer-reviewed paper, written by LRC researchers Mark S. Rea, John D. Bullough, and Mariana G. Figueiro, was published in the Journal of Pineal Research, Vol. 32, 2002. Adapting techniques from visual psychophysics, the Lighting Research Center developed a unique and efficient approach to testing alternative hypotheses about the photoreceptors that mediate melatonin suppression.

This new approach involves measuring melatonin in the blood stream after subjects spend time exposed to warm and cool fluorescent lamps. Consistent with recent findings, the results of this study showed that a combination of short-wavelength cones and rods having a spectral sensitivity that is broader than a single rod or cone receptor contribute to circadian responses. As the scientific community comes to understand this important response to light, lighting practice will likely begin to evolve too, to consider not only the visual effects of light but also its biological effects. For more information about this paper, please contact Mariana Figueiro at


Learning Education Online
Lighting Education Online Featured at RightLight 5 Conference

Dan Frering, the LRC's director of education, spoke at Rightlight 5, the fifth bi-annual energy-efficiency conference of the European Union in Nice, France. Frering demonstrated the LRC's popular new program, Lighting Education Online. He described the entire process of developing an online education program in lighting from initial concept, through surveys to determine content and delivery mechanism, to writing the content and developing the computer interface. Click here to learn more.


Resource Collection Receives Donations

The LRC Resource Collection, one of the largest library collections of lighting information in the United States, has received two generous donations to its collection. The first is a gift of back issues of two journals: Vision Research and Investigative Ophthalmology and Visual Science. The donated issues are from the 1970s, 1980s, and 1990s. These journals are difficult to find and highly relevant to the LRC's work. They were a gift from Gil Kandel, a retired psychiatrist from Brunswick, New York. Also donated: a collection of 14,000 35-millimeter slides from Ruth Zekowski, the widow of Illinois lighting consultant and regional IES president Jerry Zekowski. The LRC deeply appreciates both donations.

The LRC Resource Collection has a multidisciplinary focus encompassing all aspects of lighting. It contains research papers, reports, articles, manufacturer information, and more.


NCQLP Offers LC Exam

The National Council on Qualifications for the Lighting Professions (NCQLP) will offer its 2002 LC Exam on November 2, 2002. The registration deadline is Sept. 27, 2002. Early registration (for discounted fee) is August 16, 2002. Go to for more information or to download the LC Candidate Handbook.


About the LRC

The Lighting Research Center (LRC) is part of Rensselaer Polytechnic Institute and is the leading university-based research center devoted to lighting. Founded in 1988, the Lighting Research Center has built an international reputation as a trusted and reliable source for objective information about lighting technologies, applications, and products. Its mission is to advance the effective use of light and create a positive legacy of change for society and the environment.

2002 Rensselaer Polytechnic Institute, Troy, NY 12180 USA.

Rennselear Polytechnic Institute