Neutual density filter and long exposure

Pictures in this album were all taken from Pier66 in Seattle, between dawn and pitch black night. Most of them were under long exposure (5~60 seconds). Some were taken with neutral density filter. For examples:

• P7137679 is taken in early dawn with 5s exposure, with .9 neutral density filter plus a .6 graduated neutral density filter.
• P7137705 is taken in late dawn with 40s exposure, with .6 neutral density filter and a polarizing filter. It was already dark at that time, lights in building is on.
• P7137712 and P7137721 are both 50s exposure with only a polarizing filter, they were taken in dark.