In part II of my series examining Sony APS-C standard “walk-around” zooms we look at the performance at the 16-18mm widest focal lengths.
The bulk of this series of posts consists of a huge dump of 100% crops from test shots that I took in my backyard and up the hill from my house during the single evening I had to work with these lenses. Unfortunately it was a partly cloudy day and the light was quite variable. Tests were shot with a A7 RII in APS-C mode (since my a6000 needs a sensor cleaning). I also took some test shots with my Batis 25mm in full frame mode for comparison. The Batis crops where cropped to the same field of view as the APS-C tests then downsized to match the pixel dimensions of the cropped images. At the wide end the corner crops for the 16-70 where moved in a bit to match the crops from the other lenses. Here’s a sample full size test image.
The rocks are in a straight line and should all be in the plane of focus. Let’s look at some results.
Center Sharpness
The Zeiss 16-70 is ok in the center at f4,
improves significantly at f5.6 and peaks with a slight further improvement at f8.
The 18-105G is probably a bit better than the Zeiss at f4,
compares pretty well with the Zeiss at f5.6,
but starts to fall off noticeably at f8.
Moving to the 18-200 lenses they are both surprisingly consistent from f4 to f5.6 to f8, I can’t really perceive a difference, but the 18-200LE clearly lags behind the original in center sharpness. Here they are at f4.
For reference, here’s the Batis 25mm. At the widest angle, with the exception of the LE all of these zooms hang pretty close with the Batis at their peak in the center.
Corner Sharpness
Things definitely get more interesting in the corners. The Zeiss starts out pretty soft at f4
and gradually improves to a peak at f8, but never really gets sharp.
The 18-105G behaves just about the same to my eye, though there is not as much improvement from f5.6 to f8. I’m going to call the Zeiss and 18-105G comparable here. Note that the 18-105G has a significantly narrower field of view at the 18mm setting than the other nominally 18mm lenses.
A bit of differentiation becomes noticeable here with the 18-200’s. The original 18-200 is pretty consistently soft at all apertures here, while the 18-200LE is similar at f4 and f8 but does clean up a bit at f5.6.
And here’s the lovely Batis for comparison.
Summary at the Wide End
In the center, these lenses are pretty comparable, even throwing the Batis 25mm in the mix, with the exception of the 18-200LE which lags in sharpness. In the corner all of the choices are soft wide open, the Zeiss 16-70 and 18-105G are in the lead when stopped down with the 18-200LE a bit behind and the original 18-200 lagging in corner sharpness. None of these can match the Batis in the corners.
All content Copyright 2016 Joseph P Kenny.
