Dame Maggie Smith makes the 'Downton Abbey' cast "up their game".

The big screen legend - who resprises her role as Violet Crawley, Dowager Countess of Grantham in new movie 'Downton Abbey: A New Era' - has forged in incredible legacy in cinema, and her co-stars have found themselves wanting to impress her on set.

Speaking to HeyUGuys.com, Michelle Dockery (Lady Mary Talbot) said: "You do up your game with her. She's got this presence that you feel like you've really got to be on your best behaviour and at your best."

Kevin Doyle - who has played footman Joseph Molesley since the period drama first launched as an ITV series in 2010 - admitted he "slowly" felt more comfortable acting opposite Maggie.

He explained: "It changed over the years, didn't it? I remember being terrified to start with. But slowly over the years, she puts out the feeling that maybe she likes you a little bit."

However, Hugh Dancy - who joins the cast for the new movie as Jack Barber - joked he didn't get to work with her enough to develop that rapport, and he's worried he "embarrassed" himself.

He quipped: "I don't think I had time to get to that stage. A couple of scenes, and mostly it was me thinking, 'God I was bad in that bit. I've really embarrassed myself in front of Dame Maggie.' "

Meanwhile, Robert-James Collier jokingly played down her talents on screen, noting her accomplishments and saying he doesn't understand the "fuss".

He teased: "I don't rate her. I do not rate her as an actress. Don't know what the fuss is. Never rated her. What's she won? A couple of Oscars, that's it!"