SINGAPORE - The idea was simple - take an extremely high-resolution panorama of the National Day Parade crowd at the floating platform that viewers can zoom in on, close enough to spot their own faces.
It would be like a 25,000-member family photograph of the nation gathered for Singapore's 52nd birthday.
But the execution was not at all simple - it required special equipment, including a robotic camera mount called a gigapan, several dry runs and even certification to work from heights.
To capture the gargantuan shot, a camera with a telephoto lens was placed onto the robotic camera mount, which moved the camera in precise movements to make successive overlapping photos that were stitched together afterwards to form one gigantic photo.
The gigapixel consisted of 752 images shot with a 500mm lens.
Two of The Straits Times' executive photographers - Ong Wee Jin, 34, and Mark Cheong, 29 - spent months preparing for the crucial moment on Wednesday (Aug 9).
Mr Ong, who has been with Singapore Press Holdings for nine years, first approached the NDP executive committee with the idea in May.
Mr Cheong had to go on a course and be certified to work at heights. To get the shot, he had to climb a 23m-tall LED tower, one of the four that support the LED screens on the main stage at The Float @ Marina Bay.
"We also had to engage a work-at-height safety supervisor and a safety assessor for each climb," said Mr Cheong, who has been an ST photographer for five years.
"Numerous tests were also done with the camera and gigapan, both at the office and the platform, to make sure all would pan out smoothly."
The process started with getting access to climb the scaffold backstage.
Setting it up alone - including climbing, rigging and setting the camera in place - took almost an hour and a half. What made the task even more challenging was the fact that the photographers were allowed to be up there for only a short period of time.
"For this, we did several dry runs and set a timer on the gigapan so it would start shooting only about an hour after we set it up," said Mr Cheong.
"The gigapan took about an hour to finish the shoot from 6pm to 7pm, and there was the challenge of varying light levels due to the setting sun."
The final panorama took about a day and a half to complete as it needed to be stitched together.
The shoot was a collective effort by photographers, ST Digital and external parties, including the rigging supervisor, said Mr Cheong.
ST's picture editor Stephanie Yeow and Mr Ong spent three days and two nights stitching the photos together.
ST Digital colleagues created the interface that would allow users to zoom in and spot themselves.
"It took a lot more effort than I had imagined," said Mr Ong. "It is the first time a gigapixel is shot at a live NDP and our first attempt at producing one.
"Although the final image is not perfect, as you can still see a lot of stitching flaws, I hope that many who attended NDP will still be able to say 'hey, I was there!' and be part of something they can remember about the parade."