Most involved with the project (except for Williams, who is preparing to play in Vienna) attended, including directors Peeter Rebane and Russel Thomas - who has previously captured U2, Björk and Muse - and producer Melanie Fletcher.

The August 20 show at the Song Festival Grounds, which will be beamed to cinemas live across the world, will rely on 22 cameras.

Fletcher, who oversaw 50 cameras at the London Olympic opening ceremony, told ETV: "It was probably twice the size in terms of the technical setup, and obviously the planning was a lot longer and it was bigger and there was more stress involved. But these types of shows are reasonably similar in that you manage massive crews and lots of cameras and technical difficulties."

Thomas explained the Spidercam filming method that will be used - a first for Estonia: "Spider cameras are a system on wires where we have four big tall posts - around two here and two up there in the field. And there's a camera attached to it and it can go anywhere between those four posts, and it can go very fast or very slow. And it's got a stabilized lens so it can go quite close into Robbie and it can kind of just pull out and pull out and so you see this beautiful field of people."

The on-location crew for the live concert film includes 29 people, most Estonians. Two cinematographers will come from abroad and there will be some photographers from the Williams entourage as well.

The concert film, produced in collaboration with ERR, will be released late in 2013.