Here are some suggestions of places to take photos and visit:
-- Golden Gate Park panhandle and Haight Street area, for street photography
-- Crissy Field along the Presidio shoreline down to Fort Point beneath the GG Bridge
-- The Embarcadero area at the base of Market Street, as well as the public market in the Ferry Building (farmers market outside on Saturdays)
-- Photo buffs should not fail to stop by SFMOMA on 3d and Mission, w/ its wonderful photography collection and excellent visiting exhibits.
-- The Yerba Buena center across the street from SFMOMA has interesting architecture and is also good for street photography (or you can simply walk up Mission St.).
-- I would walk down Grant Ave. through Chinatown. Yes, there are tourists, but the area is not that touristy. (In contrast, I would avoid Fisherman's wharf, Ghirardelli Sq.).