Foggy Days in San Francisco

San Francisco in the summer means fog, most of the time.  The heat from the famous California agricultural valley pulls the fog in from the ocean.  In addition to freezing the tourists, it wrecks havoc with photographing one of the most famous San Francisco sites – the Golden Gate Bridge.  After all, the Bridge spans the gap between the northern Marin penninsula and the San Francisco penninsula, the Gate where the Bay enters the ocean.  The fog arrives here first!

The fog comes in many forms and sweeps across the Bridge in many patterns.  On this particular day, we were approaching San Francisco from the Marin overlooks along the Bay shore and could see the fog creeping northward.  The north tower was till in sunlight.  I wanted the color of the bridge and the Marin Headlands, and so I used the telephoto lens to frame down and pointed my little focusing and light meter square at the brown hills, held the shutter button half way down to hold the reading, and then recomposed the shot.  The results showed the fog moving northward, but retained the color of the Bridge and the headlands, and also picked up some of the sunlight illuminating the fog and turning it into a rosy glow.

The important part of this is determing what you want the final shot to look like.  If I had wanted the bridge and headlands to be dark, I would have pointed the metering poing at the fog itself.  The fog would have provided a white background against a dark Bridge and hill outline.