YOU could say it is just like old times. In the depths of Nottingham Castle sits King John, clad in chain mail and furs. Not far away is the Sheriff of Nottingham. He's in a face-off with Robin Hood, poised with his bow and arrow, and surrounded by his Merry Men.

This was my first glimpse of Robin Hood: The Movie, a joint run by Nottingham Castle and Sherwood Forest Visitor Centre, launched today to coincide with Ridley Scott's new film, Robin Hood.

According to the city council the movie, which stars Russell Crowe and Cate Blanchett as Robin and Marian, is expected to bring £50m to the area on its release on May 14.

This exhibition, which it is hoped will pull in at least 150,000 visitors, is the start of seven months of activities in the city and county.

Visitors to the castle will be able to see the costumes worn by all the film's main characters. These include Russell Crowe's khaki-coloured outlaw attire and suede cloak, Cate Blanchett's demure, wasp-waist canvas corset, as well as accessories like musical instruments, pennants, maps of Nottingham and the Holy Land and gold-painted religious icons.

Other characters whose costumes feature on mannequins displayed in the Castle basement include Little John, Friar Tuck and the Sheriff. Soldiers and a warhorse ready for battle also feature.

Across at the visitor centre, you can see film scripts and videos of cast interviews or sit in a massive cart from the set.

Sonja Klaus, who designed the exhibition and also worked on the film as a set decorator, was in Nottingham for the launch.

"This is very real, this film. It shows you what it was like to live then. It's definitely not men in tights," she said.

"That's the thing that will set it apart from all the other Robin Hood films."

She said she had spent 16 weeks researching and preparing sets for the film, shot in Wales, Bourne Wood, Surrey, and Windsor Great Park.

A replica medieval Nottingham was constructed in a Surrey woodland, including a mill, corn exchange, chapel and various hovels and huts.

"I would like to think it's largely accurate to the period, although bear in mind we're making a film, not a documentary," added Sonja. She said the exhibition was a chance for people to appreciate what went on behind the scenes.

"These kind of exhibitions are always good for a film of this size. People should be allowed to see this stuff and appreciate the amount of work that goes on. It would be great if we could have a special screening of the film in Nottingham too, although I'm not sure if Universal are planning to do that."

Ridley Scott was involved in the selection of which items would be displayed. He also presents some behind-the-scenes video clips from the film.

"I think the film is fabulous – although, of course, I'm biased!" said Sonja.

The exhibition arrived in the city following a joint bid from the city and county councils, Experience Nottinghamshire and Visit Britain.

"We went to Universal and held negotiations with them," explained Sheriff of Nottingham Coun Leon Unczur. "They needed to be convinced we could do the job and, after lots of meetings, we convinced them we could.

"Already the phone lines are jammed with people wanting tickets. I think this is probably going to be the best version of Robin Hood. I'm hoping it's going to bring in around £50m to the city and county."

Meanwhile, Coun Unczur and his commission are due to finalise ideas this summer to bring a permanent Robin Hood attraction to the city. He aims for the project to be completed in four to six years.

"We are talking about a world-class visitor attraction that will have the wow factor," he said.

Alison McKay, brand manager for Visit Britain, said the Robin Hood campaign was the biggest they had launched, stretching across 35 countries. "We had to fight for this exhibition; there was an idea it might tour with the premiere," she explained.

Castle manager Dave Green said he was hoping the exhibition, which runs until October 31, would attract at least 150,000 visitors.

"Although, with luck, we'll get many more," he said.

Tickets for admission to the castle and the exhibition cost £5.50 for adults but just £1 Monday to Friday for those with a Citycard.