Here's a brief comparison of the Loxia (Planar) 2.0/50 vs. the ZM Planar 2.0/50 on an A7R.
- both lenses show (almost exactly) the same distortion
- both lenses show (almost exactly) the same light falloff
- both lenses show a very, very similar look
- the Loxia’s resolution all over the image frame is much, much higher
As in the Loxia 35 vs. Sonnar 35 thread here are again PNG-screenshots from the Capture One interface (not taken from processed files) converted to JPEG.
Make sure to view the screenshots at 100% magnification...
1- scene: Loxia on the left, ZM on the right (in all screenshots below).
The ZM-Planar shows a slightly wider field of view:
Focus is on the wall (not on the trees or on the number attached to the street lamp).
You need to stop down the ZM Planar to f4 to come relatively close to the performance of the Loxia.
2- center f2:
3- center f2.8:
4- center f4:
I’d consider the edge performance of the Loxia wide open really good… though it gets better when stopped down. At f4 the edges are usable even when really high sharpness is required.
The ZM Planar needs to be stopped down to f8 to reach a comparable level.
5- edge f2:
6- edge f2.8:
7- edge f4:
8- edge f5.6:
9- edge f8:
… at the very corners the ZM Planar comes nowhere near the performance of the Loxia … not even at f8:
So … I would say the Loxia Planar 50 is the good old ZM Planar 50… redesigned for much better resolution to meet the demands of current highres sensors.
As far as I am concerned it’s definitely a keeper :-)