This lens is stil the second-best fast AF 50 out there right now.
Most fast 50s (F/1.4 and faster) only become good or excellent at F/2.8, and generally are mediocre at larger apertures. They often even share the same characteristics when it comes to performance, i.e., not so good wide open up to and including F/2.5, and suddenly great from F/2.8 onwards, The Canon 50 F/1.4 is a good example of that, as is the Zeiss 50 F/1.4. If you look at the manufacturer's MTFs, this is corroborated, too, especially close to MFD.
When it comes to slower 50s, most are really good to excellent wide open, you normally only need to stop down 1/3 of an f-stop to have an eminently usable lens. A lens like the 50 F/2.5 CM is absolutely great from wide open, and has great bokeh to boot. It is an often overlooked gem, but for the noise of the ArcDrive AF motor.
If you need a fast 50 mm lens for Canon, on FF, there are really only 2: the 50L and the Sigma 50 F/1.4. And despite the tests here, they actually do very well. The thing is that with the current cameras, we get MTF curves like we used to get with film. The AA filter and resolution don't smother the actual rendering capabilities of the lens anymore to a bunch of flatliners <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.This means it looks as if these lenses suddenly don't perform all that well anymore, while in fact they are better than anything produced ever before. Don't forget that even the "lowly" corner resolution is about 40 lines per mm wide open, which is approximately what an amateur would get out of colour negative film in the centre, in the good old days. And you honestly have to see the images of those who have taken the time to get to know how to work these lenses to see what I mean.
And which one you choose, depends on personal preferences and budget, AFAIAC. In my case that is the 50L, basically because I prefer the rendering of the 50L way above anything else in the shorter FL range.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....