FMS - The Fluorescent Mineral Society

Golden Gate Bridge and Fluorescent Boulder - 2006 HDR

HDR image of fluorescent calcite veins on a beach boulder at low tide just outside the Golden Gate in San Francisco.

The camera was on a tripod to take about 10 bracketed exposures of the bridge. I happened to have a pocket 4 watt SW UV lamp, so I continued to take additional long exposures illuminating small sections of the boulder at a time. The HDR linearization method I used allowed compositing the layers without distorting the highlights.

Some unfiltered blue leakage from the tiny UV lamp makes the fluorescent areas look more violet than reality, but there are a variety of activators besides the orange manganese, with bits of broad spectral colors in a range of creamy yellows to pale blue.