This is a continuation of a test of the following lenses on the Sony a7RII:
- Zeiss 85mm f/1.8 Batis.
- Zeiss 85mm f/1.4 Otus.
- Leica 90mm f/2 Apo Summicron-M ASPH.
- AF-S Nikkor 85mm f/1.4 G.
- Sony 90mm f/2.8 FE Macro.
The test starts here.
In the preceding post, I reported on some left/right color fringing with the Batis 85 wide open. I went back to the on-axis color fringing samples from a few days ago and processed them in the CA app of Imatest looking at a vertical edge.
Here’s what I saw wide open:
Well, something appears to be there. The dark side has a red bias, and the light side a green bias.
If we look at an edge at 90 degrees to that, we don’t see the effect.
The big question is, is this bad behavior, or just an odd departure from perfection. In order to answer that question, we need to look at the vertical edge results for the other lenses.
Let’s start at f/1.4. The Otus:
Well, that looks pretty wonderful. How about the Nikon:
That’s more down to earth performance. Makes the Batis look good, although the Nikon is giving away two thirds of a stop.
Let’s look at f/2.
Notice that stopping down a third of a stop has substantially improved the Batis on-axs color fringing performance.
And, the good-looking, bad testing Leica:
So the Batis does not look at all bad in comparison tothe other lenses in this test.
Let’s continue on to f/2.8 so we can pick up the Sony. In fact, we’ll start with it:
Also looking good.
Not so good.
Not quite as good as the Nikon.
I won’t show you the Otus at f/2.8, since it was already so good at f/2.