Avengers: Age of Ultron isn't being kept a completely secret affair, as shooting continues on Joss Whedon's upcoming Marvel ensemble. The entire cast is now in the UK, shooting at Pinewood Studios. There, Bruce Banner himself, actor Mark Ruffalo, has decided to Tweet out a couple of cast photos, giving us our first look at the Avengers as they reassemble after the fall of S.H.I.E.L.D., as seen in the recent Captain America: The Winter Soldier.