Here is a quick process of five frames taken with a Canon 50mm F1.8 at F2.8 for six minutes at an ISO of 200. Processed with IP and RGSTR and PS. Obviously used the 5DH. The field of view is 41X27 degrees.
2.2MB
http://users.bigpond.net.au/avandonk/Sag_50mm.jpg
Gradients are a real pain with fields this wide. If this was easy everybody would be doing it. Will try to get it better but it is a 'naked eye view' of the sky if we had better sensitivity for low light.
I even managed to squeeze in Corona Australis.
Bert