Originally posted by jeryst I know technically, there is not much difference, but I was just wondering about photo-wise. Is there enough of a difference between the two to justify me saving my money up for the f1.2 in case I run across one, or would it be better to just get another f1.4 that supports autofocus?
If you shot the same subject under teh same conditions wide open at f/1.2 and f/1.4 with, say, their "A" versions, printed them big (assuming both are in focus, exposed properly, etc), and laid down a series for a Coke vs. Pepsi face-off, you'd probably see no difference in practical viewing unless someone knows how to count aperture blades (9 for 1.2, 8 for 1.4). Good luck with that.
For aesthetic performance, no difference.
As for the comments about newbies getting a fast fifty. Absolutely. Great advice. It gets people moving their feet and allows for greater DOF and isolation opportunities that are the bread and butter of good photography.