Contax Carl Zeiss T* Planar 50/1,7: the Sharpest 50mm ever?

someone asked me what some of these lenses look like, so here is a shot I took today of the long named:

" Contax Carl Zeiss T* Planar 50mm f1.7 MMJ" phew, say that 9 times fast!

This lens is interesting and also cool for a few reasons

1: A lens built in Japan  ( the J in MMJ) by Kyocera for Contax under license from Carl Zeiss

2: Contax /Yashica mount, named bacause it was used for 2 brands of lenses, the contax one here and also the lesser quality ( some say equal) Yashica lenses that can be bought for about 1/4 the price of these Zeiss ones , but they use the Zeiss technological input

3: Its a 50mm 1.7 lens, and is one of the rare lenses that is sharp at its widest aperture ( 1.7) a lot of lenses are incredibly fast , but when they are wide open youget a lot of chromatic aberration, or fringing , or the lens is just plain soft. This lens is sharp, has a tiny bit of purple fringing if the light hits the lens just so, and for CA I coudlnt see any of note . It is also regarded by some people to be one of the, if not THE sharpest 50mm lens ever made, but that is highly debated all over the net , google it and see

For this shot: ISO 800 and taken with my new 50mm f1.4 FA Pentax lens on my KX, and I already think its not as sharp as my Takumar 50/1.4 , but I need to do some more testing on it. It was placed on a C/Y>EOS adapter and lit by 2 x 100W spotlights inside a homemade lightbox on a piece of black polished slate