“Fluorescent paint used to make me think of neon – bars and beer – so I never really thought about using it. I didn’t think it was an important pigment.

“But then I began thinking about how modern humans spend half of their time awake at night, unlike the ancients who slept through it. The night holds their stories. That is today’s reality. I realised that by using fluorescent pigments, I could capture night scenes.”

The fluorescent waterfalls, like much of the artist’s work, are large; Falling Water is 1.63 metres by 2.26 metres.

For Senju his waterfalls are metaphors for the earth itself.

“Waterfalls are very interesting, as they are continuously moving. That makes them difficult to paint, and hard to sketch. One day, I felt moved to paint one because of their extreme beauty.

“When you think about what we have on earth, there is gravity, water and temperature,” Senju continues. “You can say that the world is like a waterfall, as it has those three things. So when I am painting a waterfall, I feel I am painting the earth itself.”

And while his works may be reminiscent of Abstract Expressionists, such as Mark Rothko, he says they have a different genesis. While Rothko and others tried to express their inner world, Senju wants only to capture the outside world. “My art is not self-expression, it is an expression of the world.”

At Sundaram Tagore Gallery, 57-59 Hollywood Rd, Central, until June 9. Opening hours: Mon-Sat, 10am-7pm, Sun 11am-7pm. Tel: 25819678