Here are a couple of cool videos in slow motion that Lasse Karlsson did recently. Those of you who fish relatively long lines might be interested in them and those who fish glass rods may be too.
He is casting two rods in the same hand, a Sage TCX and a Berkeley 75% fiberglass?25% graphite mix. They are taped together and he's holding both handles but has his finger between them to they don't bang together during counterflex and rebound.
Notice the difference in the loop shape on the un-hauled cast in the first video, and then compare it to the loop shape in the second video.