Roger Cicala from Lensrentals testes all the best 50mm lenses. The best lens is the 8000 Dollar/Euro [shoplink 27099 ebay]Leica Summicron f/2.0 (here on eBay)[/shoplink]. But the surprise is “again” the new Sigma 50mm ART lens. Roger writes:
I think it’s pretty cool that two SLR lenses (Zeiss Otus and Sigma ART) are able to hang right there with the f/1.4 Leica lens, the Summilux. Price-wise, you would hope the Otus would, but certainly the Sigma, one of the least expensive lenses in the test, has to take honors for hanging with the best at a tiny fraction of their price.
And the Sigma is very close to the Summicron lens at f/2.0 aperture:
Now let’s hope the 24mm and 85mm f/1.4 lenses coming at Photokina will be as good as the 50mm ART!