PEOPLE stared at him in wonder during the three days it took to complete his detailed drawing of the Sydney skyline. But for the autistic British artist Stephen Wiltshire, it was a cinch.”Big drawings are very hard to do,” he said. The one of Sydney – about a metre squared – was much smaller. Mr Wiltshire drew a 10-metre-wide image of Tokyo in 2005. But for any size, ”I always concentrate doing drawings.”The artist – brought to Australia for Autism Month – attracted a stream of onlookers as he created the work at Customs House in Circular Quay from memory. He had prepared by taking in the view from Sydney Tower for about 40 minutes on Tuesday. He liked Sydney’s shapes, he said.The artist listened to music as he drew, smiling often.The 36-year-old MBE says little about his gift which has brought him world acclaim. But his sister, Annette, who travels with him, thought the way he looked at cities had to do with him absorbing ”lines and horizontal-vertical … The number of windows as well.”I think probably what’s more difficult for him is trying to remember the streets and the things that are not familiar to him … perhaps a sculpture or birds.”But she was still mystified by his ability. She knows, though, that the recognition he has received for his drawing ability has helped him develop. ”It’s worked very well for him – it’s helped him come out of himself more. He’s less withdrawn.”Autism Spectrum Australia, or Aspect, which arranged Wiltshire’s visit, says about 20 per cent of people on the autistic spectrum – about 130,000 Australians – are believed to have savant-like abilities but only about 100 in the world have a talent as advanced as Wiltshire’s.The artist will sign work and talk about it at Customs House today from 11am. The picture will be on show – with his other work – until May 16 when copies will be sold to raise funds for Aspect. Autism Hour is from 9am today.