This photo was taken at Luna Park, Milson Points on February 25, 2012. At that almost new moon night, the weather was forecasted as clear, 5% chance of rain, and about 5-10% of cloud coverage.
I and some of my close friends waited until the sky was clear, then starting capture the stars and light of Sydney. From 02.00-04.00AM, I captured almost 40 shots (180 seconds each @ f/5.6, iso 200). A cheap remote control (about $15), ordered from eBay, served me very well.
In post processing, I imported all photos to Photoshop by using [File\Scripts\Statistics...] command. Then, an image statistic window will appear. Use stack mode: Maximum and import all photos. Relax with a cup of coffee, then with in 5 minutes you will received a star trails shot, waiting to the next processing steps.
Note 1: No filter used in this shot. I separately captured the bridge about 2-3 shots with different exposure and blended them later with the star trails shot in Photoshop.
Note 2: The higher ISO, the more stars in the photo.
Note 3:The longer focal lens, the more movement of the captured stars. For more information visit:500px.com/photo/5221531
Note 4: Tilt shift lens offer us much more prominent effect of star trails as we could capture the bride and the sky separately. Nikon 24mm. Tilt shift is the best in this location. Visit OAKY's star trail photo taken in the same night as mine with the tilt shift lens:500px.com/photo/5364559