One of the more cool things about the A7/A7r is the opportunity to use adapted glass on these bodies. As well as the Zeiss 35 & 55 FE I have a decent set of glass in C/Y mount, which I am working my way through, to find out what’s good and what’s not so good. The most obvious thing to do was to pit the Zeiss FE 55/1.8 Sonnar against my Contax fit 50/1.4 Planar. Typically Sonnar designs are sharper but slightly slower than equivalent Planars. The FE lens has been Rated as the sharps AF lens available and not far short of the monster Zeiss 55/1.4 Otus, so it would be interesting to see just how good it is against, arguably the sharpest of the classic 50/1.4 lenses from the 35mm film days. Having made a few shots with the Sonnar on my NEX-6 before the A7 arrived I had been stunned by the sharpness and therefore expected the Sonnar to trash it’s older Zeiss stable-mate.
I’m not hugely scientific bout lens testing, but I think that shooting a lens in the real world very quickly tells you if you are going to like it. Personally, I’ve always liked the 50mm Planars I’ve owned over the last few years. I also knew from the first shot that the new 55mm Sonnar was a bit special. I don’t really have a preference in terms of build, though the need to adapt the C/Y lens does introduce the potential for misalignment but I think I’ve been quite lucky with my (cheap Chinese) NEX-C/Y adapter as I’ve not noticed any major quality issues on the lenses I’ve tried.
In the end I was pleasantly surprised by how close the Planar came to the Sonnar. It’s clearly not quite as sharp at pixel peeping levels but by f/4 it’s really not far behind at all, it also has slightly lower contrast and a warmer colour rendition – which could have it’s uses.
I had to buy some glass as my trade in massively exceeded the body only value of the A7r but if I hadn’t been able to get the FE 55mm lens then the Planar would have given about 95% of the IQ for no further outlay. Obviously as I do have the FE it will be the mainstay of my prime lens kit from here on in.