Just before I headed to Europe at the beginning of the summer, I bought the Sony 28mm f/2 wide angle lens. It's only $450, cheap for the Sony lenses that go with the A7-series full-frame mirrorless cameras. I also picked up a used Sony A7 II, so I had a camera to shoot in low light at high ISOs where my regular Olympus micro four-thirds kit doesn't deliver the image quality I want.
I was quite happy with the images coming from the Sony and since it's small, I considered it a nice addition to my Sony gear, which consists mostly of small lenses to accompany my main kits, the Olympus MFT setup and a Canon setup with mostly long lenses.
After my return, Carl Zeiss shipped over the two new Batis lenses, the 85mm f/1.8 and the 25mm f/2. My review of those will follow soon, but suffice it to say, it will be positive.
Today, I decided to try out the options I have with wide angle lenses for my Sony's. Part of me was just curious. Another part of me wanted to know if I should spend the money on the Batis over keeping the Sony 28mm. This was just a quickie test to compare sharpness.
I threw in some other lenses: the Canon 24-70 f/4 IS with a Metabones III adapter and a classic manual focus Olympus 24mm f/2.8 with an adapter.
Sad to say - for my wallet - is that the Batis blew all the other lenses away, at all the tested apertures from f/2 up to f/5.6. The other lenses catch up a bit and the center becomes hard to distinguish in terms of sharpness as the aperture closes down, but corner performance never equals the Batis at each given aperture. The Canon comes closest, followed by the Sony 28mm. Of course, the Canon's smallest aperture is already up to f/4.
As such, the other lenses are fine stopped down, but once you start comparing them to the Batis, you realize what could have been.
That said, I'm still not sure I'm willing to carry the Batis everywhere with me when the Sony is smaller and cheaper and delivers acceptable results when stopped down. I do know that I want that Batis, though.
So, a word of warning: don't compare your other lenses to the 25mm Batis. It might cost you...
By John van Rosendaal