I finished off my testing of primes on A7r with Zeiss UltraPrimes (cine lenses) 32mm/t1.9 and 24mm/t1.9 against Leica Summiluxes 35/f1.4 and 24/f1.4.
The Ultraprimes are built for the S35 cinematography gate/sensor which is similar to APS-C in size. Before, I found out that the 85mm UP covers the A7r sensor (36x24mm) wihout noticable vignetting. The 50mm UP had some vignetting.
I expected the wide UP's to have even more vignetting but to my surprise the 32mm UP had it less than the 50mm UP, and the 24mm UP was comparable to the 50mm UP in that respect. It does not mean unfortunately that Ultra Primes can be some kind of "Master" lenses for the A7r. They are built for S35 frame and beyond that area the image quality deteriorates visibly--vignetting or no vignetting. Apart from that, they weigh a ton , are the size of a small melon and cost 15k$ apiece. So how do they perform on the A7r against much cheaper (yes!) and smaller Leica Summiluxes? And the Sony 35/2.8 FE?
(I had discussed the 85 and 50 UPs before.)
The 32mm UP wide open (f1.7/T1.9) is better than the Summilux 35/1.4.
It is as sharp as might be and very contrasty. The summilux is softer. It picks up by f.1.8 and they get equal. Both are better at f2 than the Sony 35/f2.8 FE wide open.
And it remains so until f8. So the Sony is not as strong a performer as the amazing Zeiss Sonnar 55/1.8. Yet...it is very good and comparable to other top FF lenses (Nikon D800 Sigma 35/1.4 which I wrote about before).
The 24mm UP beats visibly the Summilux 24/1.4 while both wide open. No contest. The 24mm Lux is worse here than the 35mm Lux. I wonder very much what the Zeiss 24-70/4 FE will be like at the wide end.
The 24mm UP vignettes worse than the 50mm UP.
The Summilux does not exhibit the discoloration seen on other Leica ultrawides (Elmarit 21/2.8) but still it's horses for courses. The only reason to put it on the A7r is when one needs the f1.4 aperture--where it is soft and poor at 2/3rd from the center.
The interesting thing is that Ultrprimes and Summiluxes at all f-lengths show CA wide open and the Sony FE glass does not. It must be some corrections of raws in LR5.3 that acts on demosaicing.
After finishing this run of testing I came to one conclusion.
If Sony together with Zeiss manage to deliver the FE line of lenses at the current performance/price ratio level, there will be little reason to use exotic "master" glass like cine Ultraprimes or Leicas.
Obviously tuning the lenses to sensor works here wonders, especially with the automatic software corrections in Lightroom (CA, I don't know about distortion).
Leica had a more difficult job to build a sensor compatible with their film lenses.
Indeed, the Leicas perform best on Leica bodies. Not so good on the Sony FF sensor.
Finally I am underwhelmed by the performance of cinematic Ultra Primes. Sure they are great, but at 15k$ apiece and with the size they are I expected wonders in the center. Meanwhile the wides are better han Summiluxes but the 50mm was at par with the Konica Hexanon (tested before). I did not have a portrait FF lens to put against the 85mm UP.