Three giant glass plate negatives – measuring 1.35 x 0.94 metres (53” x 37”) – are the world’s largest nineteenth century wet-process negatives. These colossal images record views of Sydney Harbour in 1875, documenting the future site of the World Heritage-listed Sydney Opera House, with the burgeoning colonial city beyond still surrounded by virgin bush.

These images of Sydney Harbour were created for an ambitious publicity campaign mounted in the 1870s to sell the wonders of Australia to the world. This campaign was funded by German-born entrepreneur Bernhard Otto Holtermann, who made his fortune at the gold diggings at Hill End.

Holtermann worked with a young Australian-trained professional photographer, Charles Bayliss, to design a 23 metre-high purpose-built tower, turning the three-metre-square room at the top into a giant camera. There Bayliss and Holtermann created the world’s largest images of the time, using the wet-plate photographic process. They then toured the images across the globe.

These colossal images were created in Australia, far from the great global centres of progress and invention, and less than 40 years after the invention of photography. The survival of the giant glass-plate negatives defies belief due to their fragility. Their inscription on the UNESCO Memory of the World International Register in 2017 asserts their rightful place in the global history of photography.