Alliance for Lighting Information

Sam Berman's Comments on ALI's PIER Review

I agree with most everything that Jefferey [Knox] stated with one possible caveat. If an exterior nightime task was dominated by a demand for good peripheral vision then the work at LRC [the Lighting Research Center] shows that there is a slight benefit for scotopically richer sources, i.e. MH, over scotopically deficient sources, i.e. HPS. This in turn can be used to argue for such a task condition that compared to an existing lighting design using HPS lamps, one could achieve the same peripheral visual performance with less MH lumens. However if one did this there would most likely be a reduction in straight ahead (foveal) visual performance because that is driven by the usual photopic lumens.

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