gjl711 wrote in post #15282850
Found this. Very informative article. If I read it correctly, the Canon f/1.4 is probably the best all around winner in some cases by quite a bit. The Canon f/1.2 totally smokes everyone at f/1.2.

The Siggy is sort of average being pretty good but doesn't out resolve anyone at any aperture. The thing that surprised me was that the the Ziess lenses are really no better than the Canon f/1.4.
http://www.lensrentals.com …1/the-great-50mm-shootout
The thing to be careful of in this report (which the author painstakingly points out in the second section) is that this covers nothing more than sharpness.
I've owned four Canon 50mm lenses (50/1.8, 50/1.4, 50/1.2L and 50/2.5CM).
At apertures below about f/2.8, the first three are pretty close in sharpness. If anything, I guess I would say I found the 50L to be a little better below f/2 and the other two to be better above f/2.8. But they are really close.
But I think for these lenses any tiny difference in sharpness are probably not what would drive anyone to the 50L. Obviously, the 50L is a huge amount more money, and I'll be honest in stating that unless you can easily afford it I would be careful in thinking it will feel like a good deal.
That said, I had one major and one minor issue with the 50/1.4 and the 50/1.8 that finally made me choose the 50L.
Major - Both of the cheaper Canon 50mm lenses have poor AF performance. Both are innaccurate in general, and I found they would give up and refuse to focus in light levels where slower lenses (like my 24-105L) were still going strong. The 50/1.4 would just rack back and forth, I'd change to something else and it would lock. Happened all the time.
Minor - Both of the cheaper Canon 50mm lenses have poor bokeh, and I'm the kind of guy that usually doesn't worry about bokeh too much. About the only Canon lens I have with worse bokeh is the 24-105L. The problem is related to both bright ring effects and doubling and the outcome can be some really busy blur regions when you get the right conditions. The 50L is one of Canon's best for bokeh by comparison.