It was a Friday night and The Straits Times executive photojournalist Alphonsus Chern was regaling the audience of 1,100 people with a talk about hips and crotches.

Last August, he covered Prime Minister Lee Hsien Loong's visit to the White House. Given his smaller Asian frame, he had to jostle Caucasian photographers who were one-and-a-half times taller than him to capture images of then United States President Barack Obama and PM Lee greeting the crowd.

Mr Chern, 37, pulled away from the media scrum and positioned his camera lens between the hips of two photographers on ladders.

"That strategy enabled me to get the VIPs in the centre of the frame," said Mr Chern, who has been with ST for nine years.

About 100 people turned up for the free talk yesterday and another 1,000 watched it live on Rings TV app, a live streaming platform.

Held at the library@orchard, the talk is the 10th in a series of 12 under the askST initiative where readers can engage ST correspondents on topics such as finance, healthcare and education.

The series is a result of a partnership between The Straits Times and the National Library Board.

Raucous laughter broke out when Mr Chern recounted his first sports assignment. He was at a basketball match and decided to stand just behind the white line of the court, facing the hoop, to snap his photographs. He later realised that it was not a good idea. "One player's momentum took him over the line and his crotch came crashing into my lens," said Mr Chern.

Data scientist Zhang Yi, 34, said of Mr Chern's talk: "It was interesting how he juxtaposed the final picture next to a shot of himself taking that photo to show how the picture came about."

The next talk on March 31, also at library@orchard, by ST's senior correspondent Lorna Tan is on "six things you did not know you could do with your CPF".

Readers can e-mail questions to askst@sph.com.sg or submit them at www.straitstimes.com/askst.