I was tired when I typed that post you're completely correct a full stop would be a 0.8 which isn't even made and would probably be useless anyways lol. I still stand by my statement 1.8 if you're on a budget 1.4 if you have the money to burn. Personally I've never seen a picture shot with a 1.4 that made me want to rush out and upgrade. The only reason I might even consider is that under extreme zooms in editing the bokeh in the 1.8 has a weird shape whereas in the 1.4 or 1.2L it's more rounded but then again that's more splitting hairs than anything. At the end of the day a 50mm is just a great lens to have in the gear bag no matter where in the range you've bought into.