I have long felt and have been wanting to start a thread about 50mm lenses and how poor they actually are in design, perhaps with the exception of Leica, where focus shifts are quite the norm and whether one actually acknowledges this or not, and to the varying degree of acceptance.
While no one would argue that 50mm lenses are difficult to design and make, we are always in search for improvements and take it where we can!
I had come from full frame Nikon, and perhaps awful is too harsh a word, and an exaggeration for their 50mm f/1.4. However, with newer cameras especially in full frame, we are seeing increased pixel count and new photosite arrangements in the sensor which now brings lens design to show their limitations or exposure their short comings.
Carl Zeiss at Photokina 2012: new Distagon 55mm f/1.4, ZM surprise, mirrorless lenses | Photo Rumors
More recently, I have found the Canon 1DX showing more prominence in the 50mm f/1.2 lens characteristics I have, which I have always felt is second to none used on the 5D bodies while still offering AF capabilities. While I'm still investigating this for personal reasons and nothing is conclusive yet, I know the lens design is subject to scrutiny.
The new Zeiss lens is a 55mm, although not exactly a 50mm lens, I hope this will be a catalyst for newer design by the major manufactures of cameras and lenses. The latest Leica summicron with the floating element is supposed to be it's highest performing 50mm lens made. Having used the one before this, I have no reason to argue against this, and felt this lens was amazing despite its maximum aperture of f/2.
Now Zeiss will offer this new lens over their previous older designs of the f/1.4, and very good performing f/2 with macro capabilities. I really hope this is the lens that will make a far cry towards influencing those who care about shooting 50mm focal length primes on a full frame camera, and help see newer 50mm lenses on the market.
Anyways, if for nothing else, I'm just happy about a new manual focusing Zeiss lens!