Filming got underway on Guy Ritchie's latest film project, Sherlock Holmes, in London this week with Robert Downey Jr surprisingly donning a bowler hat, rather than the character's traditional deerstalker, to portray the world-famous sleuth.
Looking as though he had stepped back in time - takeaway coffee cup aside - talented actor Robert seemed focused on the job as he joined director Guy at historic St Paul's Cathedral for the film's first day of shooting.
Due for release next year, the movie also stars British actor Jude Law as the detective's sidekick, Dr Watson, as well as Wedding Crashers actress Rachel McAdams in the female lead and Mark Strong, who recently worked with Guy in RocknRolla, as the villain.
One thing the Iron Man star won't need to worry about during the shoot is his British accent, which he mastered while preparing for his Oscar-nominated portrayal of iconic comedian Charlie Chaplin.
"At the cast read-through, Robert's British accent was so good as Sherlock I remember thinking: 'He's got a Brit inside him, that man,'" revealed his English co-star Kelly Reilly.