Christopher Nolan has heaped praise on fellow director Zack Snyder after he wrapped shooting on Man Of Steel, calling the filmmaker's Superman blockbuster far more challenging than his own Batman franchise.

Nolan, who concluded his Batman trilogy this year (12) with The Dark Knight Rises, is a producer on Snyder's upcoming Superman movie, which stars Henry Cavill as the comic book icon and his geeky alter ego, Clark Kent.

He is convinced Snyder faced a much tougher task creating his superhero universe as more special effects are required in the post-production process, but he assures fans they will love the finished product when it hits theatres next summer (13).

He tells The Hollywood Reporter, "Zack was the perfect man to take this on. He is unbelievably skilled at creating a coherent, cohesive world - whether it's a very stylised world, like (2006 action movie) 300, or something that's more challenging, more varied, like he did with Watchmen.

"In my honest appraisal, taking on Superman and creating that world is far more difficult than creating the world of the Dark Knight. He has a lot of finishing to do on the movie - it has a very long post-production schedule because, unlike Batman, Superman flies.

"I actually feel guilty talking about it because I'm sitting here having nothing to do to it. I try to be as supportive as I can, and I'm just amazed by what he is doing. It's not something I would know how to do."