Alec Su (left) teams up with Wang Kai and Zhang Luyi (right) to promote his new film. [Photo provided to China Daily]

In the late 1990s, it would be hard to imagine Alec Su behind a camera. Then, the Taiwan star, who shot to fame with the band Little Tigers, was a heartthrob thanks to the hit television series My Fair Princess.

But now, Su is leaving the spotlight to his cast as he aims to be a good director.

Su was in Beijing recently to talk about his second directorial feature, The Devotion of Suspect X, a Chinese adaptation of Japanese author Keigo Higashino's classic novel with the same title.

The Devotion of Suspect X is widely regarded as one of Japan's best crime novels.

The book, which has received a series of awards in Japan, the United States and the United Kingdom, was adapted for film in Japan in 2008 and South Korea in 2013.

Both versions received critical acclaim.

But for Su, the previous success has only added to his anxiety.

"It (the filmmaking process) was very difficult," he says.

"I knew what was happening online, which put me under a lot of pressure."

When Su was picked to direct the film earlier last year, many diehard fans of the book questioned the Chinese investors' decision.

Su's directorial debut, The Left Ear, adapted from Rao Xueman's namesake coming-of-age novel, got just 5.4 points out of 10 on the country's one of the most popular review sites, Douban.com.