Actor Benedict Cumberbatch has pleaded with fans outside the Barbican theatre in London not to film his stage performance of Shakespeare's Hamlet.
In a video shot outside the stage door, Sherlock star Cumberbatch told a crowd of supporters about "cameras and red lights" he spotted in the audience.
"It may not be any of you here but it's blindingly obvious," he continued, adding it was "mortifying".
The actor is starring in a 12-week run of the play.
Although on-the-day tickets have been made available, the 100,000 advance tickets were snapped up in minutes when they were released in August last year.
Some tickets are currently being offered for up to £650 on secondary-ticketing sites.
In the video clip, which was shot post-performance, Cumberbatch said: "I can't give you what I want to give you which is a live performance that you'll remember, hopefully, in your minds and brains whether it's good, bad or indifferent, rather than on your phones."
He added, "There’s nothing that's less enjoyable or supportive as an actor on stage experiencing that."
The actor, 39, told the assembled fans that they could feel free to take pictures of him outside of the auditorium.
"What I really want to do is try and enlist you. I don't use social media and I'd really appreciate it if you did tweet, blog, and hashtag this."
Cumberbatch is not the first actor to have criticised fans for using mobile phones during a performance.
In 2013, James McAvoy scolded an audience member whom he caught filming his performance of Macbeth at Trafalgar Studios.
Last year, during a performance of Clarence Darrow, Kevin Spacey was distracted by a ringing phone at London's Old Vic theatre.
"If you don't answer that, I will," he said.