Gwyneth Paltrow and Jude Law attended the UK premiere of their new film, Sky Captain and the World of Tomorrow, on Monday night.
Gwyneth Paltrow and Jude Law hit the red carpet together
The red-carpet event in Leicester Square was Paltrow's first London premiere since the birth of her baby daughter, Apple, in May this year.
In the film she plays a reporter who joins forces with a heroic pilot, played by Law, to save the world.
Sky Captain and the World of Tomorrow has already topped the US box office.
The £38m film also stars Angelina Jolie - who was not at the premiere - as feisty eye-patch wearing fighter pilot Franky Cook, and Irish actor Sir Michael Gambon.
Set in 1930s New York, the sci-fi thriller was made without sets or location and filmed entirely against a blue screen.
Computer graphics were used in post-production to add the background and other images.
Paltrow, who celebrates her 32nd birthday on Tuesday, said: "It's a difficult technique but it was actually fun. You've just got to use your imagination."
Law added: "At first it was tricky and it was difficult to keep a straight face then we got used to it."
Film legend Laurence Olivier also appears in the film - 15 years after his death.
He is resurrected as villain Dr Totenkopf through the use of old film footage and computer wizardry.
Law's ex-wife Sadie Frost - who was also at the Leicester Square premiere - co-produced the film.
Frost said: "I haven't seen Gwyneth since she had her baby so it will be great to catch up.
"I wanted Jude in the film and he has a great chemistry with Gwyneth. I'm glad that we got him."
Paltrow plays an intrepid reporter who joins forces with her ex-boyfriend (Law) to save the world from a mad scientist.
As reporter Polly Perkins and pilot Joe "Sky Captain" Sullivan, the pair fight giant robots in the fantasy adventure.