San Francisco's steep, scenic streets served as the backdrop for television shows such as "Nash Bridges" and movies including "Vertigo," "Dirty Harry" and "Milk." But in recent years, the city's iconic topography and Victorian houses have become harder to find on the big or small screen.

Only six major movies or television shows were filmed mostly in or around the city from 2008 through 2010. In the three years before that, there were 15, according to the San Francisco Film Commission.

Both...