Raincoat-clad visitors braved the chilly conditions at Circular Quay where they were rewarded with a spectacular light show illuminating the Sydney Opera House, the Harbour Bridge, Customs House and the Museum of Contemporary Art among other landmarks.

Covered vantage points at Circular Quay Station and the Toaster building proved popular with the tripod toting crowds viewing the colourful light installations.

Sydney Trains put on extra services to avoid the over-crowding on public transport that has affected the festival in previous years.

Last year's event drew the biggest audiences in the history of Vivid Sydney, with 1.8 million people attending the festival that has grown into a international tourism drawcard.

The opening night of 2014 was also marred by tragedy when festival goer Brendan Hickey died after accidentally falling into the water at Cockle Bay Wharf.

The death of the 34-year-old Randwick-based Irishman led to calls for better safety controls at Darling Harbour.

Organisers have erected temporary fencing around Darling Harbour this year, where crowds gathered on Friday to watch a laser water show set to music by the Presets.

Darling Harbour is one of 13 precincts in this year's Vivid Sydney, with new venues established at Chatswood and the Central Park complex at Broadway.

The festival of light, music and ideas runs until June 8.