Benedict Cumberbatch has revealed playing the famous detective Sherlock Holmes has changed how he sees the world.

The award-winning detective drama Sherlock is returning to the BBC for a second series in the new year with Benedict playing the title character again.

He stars alongside Martin Freeman, who plays Dr Watson, in three 90-minute films adapted from the Arthur Conan Doyle classic stories.

Speaking at a screening of episode one, A Scandal in Belgravia, at the BFI Southbank in London, Benedict said: "Our daily lives are so mundane, we get taken over by what is immediately in front of us and we don't see beyond that. We don't observe as he (Holmes) keeps on saying, we see things, and what is so thrilling about him is it all suddenly becomes a potential adventure.

"I think if you look at the example of Holmes, or at least what I have learnt from playing him, is that you see extraordinary depth in the smallest detail. It's joining the dots, that's the fun thing, building a narrative.

"So I sit on trains and I try to see, 'Is that mud on the bottom of a boot?', 'I wonder where he has been'. 'That collar looks a little bit frayed', 'I wonder whether he is has been travelling for a while or has he forgotten his washing?' You do try to piece together personal stories from bits of information."

The other two episodes to make up the series will be The Hounds of Baskerville and The Reichenbach Fall.

Created by Steven Moffat and Mark Gatiss, the first series was huge hit with audiences and won a series of accolades including two Baftas for best drama series and best supporting actor.

The second series of Sherlock is due to be shown on BBC One in early 2012.