Presenter: John Bullough
Recent research performed for the Fire Protection Research Foundation at the Lighting Research Center at Rensselaer Polytechnic Institute suggested that effective intensity, the current metric used to characterize the photometric performance of visual signals, may not be predictive of visual detection of signal lights when these are viewed indirectly or in the far-peripheral field of view. Based on previous studies by others, RPI suggested that a flashing light should increase the illuminance on the opposite wall by at least 7% in order for this increase to be detected reliably. This estimate has not been validated. In the recent Foundation study, RPI also conjectured that colored light (e.g., red) might be used for indirect visual signaling and that an even smaller increase in vertical illuminance from colored light might be sufficient to be detected reliably. Accordingly, the Foundation and RPI LRC are undertaking a project with the primary goal of identifying whether the 7% increase in light level can be reliably detected by observers with normal vision. A secondary goal is to explore the impacts of colored light.