How I Shot It - Architecture #1

I shot this from secret spot #58, but if you get out a map of San Francisco it wouldn't take you very long to figure out where this is from so I'll just tell you.  It was shot halfway up the road to Coit Tower.  This is one of my favorite areas of the city, just above North Beach, overlooking the entire city and if you're lucky you'll see the legendary parrots of telegraph hill.  They're unmistakably bright green and not quiet about there existence. I've been wanting to photograph San Francisco from here for quite some time and so after finishing another photo shoot that day, in the same area, I decided to hang out and wait for the light (both artificial and natural) to get good.  Watching the city electrify, as the night approaches, is a wonderfully meditative experience.  It happens gradually, individual windows turning on adding single squares of light, slowly filling the foreground with a mixture of tungsten, fluorescent and halogen light.  All the while the sky, depending on conditions, evolves through a color palette unique to that particular day.  On this warm March evening the typical sunset color failed to transpire and instead a rich hue of cyan painted the entire sky, slowly building richness as the natural light faded further.  This image is actually several vertical frames stitched together, and so to take 'multiple exposures' of the overall image you have to retake the entire series each time.  To keep these bracketed frames organized I shoot my hand over the lens at the beginning and end of each 'stitched' series so I know which frames belong together in the final image.  In a city-scape like this there is an exposure intersection when the sky exposure and city exposure (bathed in dim artificial light) match.  It's at this intersection when the best exposures are shot.  If the sky had been a traditional sunset, the best time to capture that color would be before the city was ready, and thus you would need to shoot separate series for the sky and city.  I was lucky in that the sky here was a cool soft cyan, not too bright and thus I could get both exposures in the same series of frames.  I'll sometimes use a split neutral density filter to drop the sky exposure by a few stops, but that wasn't needed either.  On top of this, by switching the color balance to Tungsten, it further extenuates the deep cyan color.