Shape and color
I’m drawn to interesting shapes and colors. Especially at dusk, oddball lighting from the sky and various artificial lights creates many interesting effects. The Nikon D3 is wonderful for handheld shoot at dusk this way; I used ISO 6400 with the Zeiss ZF 28/2 Distagon. The D3 seems to produce an exceptionally high success rate when handheld at low shutter speeds (1/30, 1/15)—mass and mirror damping must be contributing factors. See the new entry on my Experiments page for more examples from today’s dusk shooting.