“Harry Potter” stars Matthew Lewis and Evanna Lynch dish about the making of “Deathly Hallows”

Evanna Lynch and Matthew Lewis, who play Luna Lovegood and Neville Longbottom, respectively, have revealed some details from behind the scenes of “Harry Potter and the Deathly Hallows.”

The final chapter of the “Potter” series, which will be split into two films, features an epic battle at Hogwarts, though Irish actress Lynch says they have yet to shoot it.

"The big stuff is still to come," she told the BBC. "I like that because if it's all at the start it's a bit of an anti-climax, but they're keeping that bit until the end."

Lynch, who’s stellar as Harry’s dreamy friend Luna, said that filming was “about halfway through.”

Meanwhile, Lewis dished on the “electric” vibe on the set.

“I've done a few days which went fantastically,” he said.

"You wouldn't be able to tell it was the last in the series because the atmosphere is electric –everybody is having such a great time.”

The two “Potter” stars were speaking at the London launch of a competition offering up a part in “Deathly Hallows.”

Lynch and Lewis released 1,000 black balloons, each attached to a ticket with a code to enter the draw, from the Millennium bridge, which was featured in the thrilling opening Death Eater scene in “Harry Potter and the Half-Blood Prince.”

The balloon launch also celebrated the upcoming DVD release of this summer’s “Potter” blockbuster.