LEAVESDEN, HERTFORDSHIRE, ENGLAND -- The Harry Potter series will lighten up on the darkness and turn into a romantic comedy for Harry Potter and the Half-Blood Prince.

That is the word on set at Leavesden Studios, where the Potter franchise has established its own world, and its permanent sets, for the decade-long production of all seven movies.

Emma Watson, who plays Hermione Granger, and Rupert Grint, who plays Ron Weasley, are delighted about the comic touch on Half-Blood.

Daniel Radcliffe, as Harry Potter himself, is not as keen. Instead, he is eager to skip to the dark finale, Harry Potter and the Deathly Hallows, due in 2010.

"We've got a long haul ahead of us!" the charming yet eternally serious Radcliffe says when Sun Media wishes him luck on the current shoot. When I mention that "everyone's delighted" to have a tonal shift from the brooding atmosphere of The Order of the Phoenix, Radcliffe smiles and says:

"Everyone's 'not' delighted to be on this!" He is referring to himself.

"I think the script's great and I think it's going to be a really great film. But I'm just one of those people that, in what I'm doing, I always lean toward the dark side and I really enjoy doing the dark stuff.

"I know Emma and Rupert really, really like the lighter stories and all that. And Rupert particularly is really going to have a field day on this, because he's got fantastic comic timing and he'll be able to use all of that to great effect on this film with his relationship with Lavender Brown.

"(But) I'm actually going to miss doing all the morbid stuff, I think." So he is eager for film seven. "That's the one last hurrah, that film. That's going to be great. I really am very, very excited about the whole thing. It's going to be epic, I hope."

Watson likes Hermione going forward. "I think Hermione has a massive part to play in Harry's success. She teaches him that the only way of defeating Voldemort is through trusting his friends and having his friends (at his side). Cutting himself off from them makes him vulnerable because he has more to lose but less (vulnerable) because he has more to fight for and they can help him through it."

While Half-Blood does have dark passages it will emphasize the romantic entanglements.

"Every film has its own sort of atmosphere," says Grint. "This one, it's really, really cool. I'm looking forward to this one.

"It's got sort of a dark undertone to it because Voldemort is back and that is quite a scary time for them. But there are some really cool bits in it. Ron gets a girlfriend in it, so that's going to be quite cool."

Producer David Hayman says the humour in Half-Blood will be "slightly warmer" than seen in Potter before.

"It's much more comedy and the awkwardness of romance. And the romance goes beyond Harry into Hermione and Ron and other characters. I also think it's about characters growing apart as well as realizing the importance of one another."

As for the Half-Blood script, written before J.K. Rowling released the final book, only one change had to be made once Deathly Hallows went public. There was an awkward reference to Dumbledore's wand, Hayman says. "For obvious reasons (if you've read the seventh book) it had to be changed."