I've been playing with the Sigma 30mm f1.4 a bit more. I was initially a bit disappointed with wide open performance, but I think that was just me having set my expectations too high!
The sort of low light shallow DoF candid shot of my daughter playing that I like. I know it's not technically a good shot, and my can of Strongbow in the foreground doesn't help either!
This is a 100% crop without any noise reduction or sharpening:
Not too bad, considering the shot? It's not a 5DmkII with a 35L... One day maybe I'll be lucky enough, but not today!