Now that Timothy Spall has won best actor prizes from the Cannes Film Festival and the New York Film Critics, he finds himself on shortlists of possible Oscar contenders. The attention being paid to his portrayal of eccentric 19th-century British painter J.M.W. Turner in the movie "Mr. Turner" is both gratifying and stressful. But Spall comes to award season with a perspective that his competitors lack.

In 1996 his name was bandied about for an Oscar nomination for "Secrets & Lies." He had good reason for not feeling disappointed when he lost out. Around that time he was diagnosed with acute myeloid leukemia.

"I got a little message from the cosmos: 'Do you want an Oscar nomination, or do you want to live?' I chose the latter," Spall said, his gaze direct and disarming. "I had the kind of leukemia that you either have or you don't. It is not one you can live with. I had a look over the precipice. It does give you some perspective."

Over 35 years Spall has done it all — theater, TV, film. Children know him for playing the wizard Wormtail in the Harry Potter series, while adults might remember his Winston Churchill in "The King's Speech."

His most lasting professional relationship has been with esteemed British director Mike Leigh. "Mr. Turner" is their seventh collaboration, and the most satisfying of Spall's career. Leigh first approached him to play Turner seven years ago, but he heard nothing more about it for four years.

"I was walking around London in a desultory fashion," recalled Spall. "I sat down and looked up, and I was sitting under where Turner was born." Taking that as a sign, he called Leigh, who told him he was finally ready to make the movie and Spall should learn to paint right away.

He studied for a year with an art teacher who took him through the history of art and Turner's place as a landscape painter renowned for his oils but also a master of watercolor landscapes.

"Then we got on to how Turner worked, how he mixed his paints and how he created the effect he did. We did a full-scale copy of one of Turner's masterpieces. It took about three weeks. I learned so much during that time," said Spall, who keeps his "Turner" in his hallway at home.

He became so proficient that Leigh was able to use Spall's hands in all scenes of the master at work. That's Spall, his sleeves rolled up, spitting into the paint as Turner did.

"Learning to paint was enjoyable, but it was hard, too. Because I had a small piece of ability, I knew when [what I was doing] was [bad] or not," he said.

His research extended to uncovering how Turner presented himself to the world. "He had a hunched look mixed with a slightly odd swagger. He was famously difficult to understand because he did this grunting thing," Spall said. Incorporating a grunt into his portrayal of Turner has drawn laughs from audiences.

Leigh's method of working is to have his actors improvise their roles for upward of a year. This process allowed Spall to get inside his character's head and try to understand the reasons that Turner was unable to sustain a permanent relationship with anyone.

Based on the Turner biographies he carried around "like a student, in boxes and satchels," Spall learned that the artist ignored his two illegitimate daughters and was a randy guy into his 70s. He broke off an affair with his housekeeper, whom "he had used as a sexual convenience," to take up with a landlady, to whom he gave a phony name because he didn't like people knowing who he was.

"A lot of, shall we say, his solipsistic attitude to life was a product of his terrible childhood," Spall said. "His mother was called a raving lunatic. In fact, if she were diagnosed now she would be a violent paranoid schizophrenic. He and his father had her committed. It haunted him the rest of his life."

All the while, Spall looked for connections that could help him relate to Turner. "He was the son of a barber, and I am the son of a hairdresser, so that's a coincidence," he said.

He admired how Turner rose above his station by learning diverse subjects such as Greek mythology, Greek and Roman architecture and the field of electromagnetism. "He was a polymath. What made it interesting is that he looked like the sort of guy who would deliver the coal."

The hardest part of Turner's life for Spall to understand is how he got through it without a family to lean on. Spall stays close to his three adult children, including a son, Rafe Spall, who followed him into acting. Spall calls his wife, Shane, "my Rock of Gibraltar. She is very understanding and very protective of me.

"I am not going to go on and say I'm a tortured artist. But we know there is very much evidence that within the profession of acting and show business there are a lot of casualties," he said.

"You are constantly exposing yourself and putting yourself out there, and if you have a modicum of success, the price of that is often you get kicked square in the balls and not only that, you have to suffer public humiliation. But your intention was not to [mess] it up. You certainly didn't want to turn up and annoy everybody."