12-01-2014, 10:14 PM
Looks like, on closer inspection, there's not FW related difference in focus shift.
But there is quite a bit of focus shift, especially at close focus, which I think explains the DXO data showing it getting worse as you stop down.
That's a bugger. But other than that it's very nice (except at 35mm). Sharp across the frame from wide open, contrasty, and with surprisingly smooth bokeh in situations where you can see any (i.e. at close focus wide open)
the long end is a bit uncontrasty, and needs stopping down to get sharp. But it's a terrific 16-18-21-24-28 f4...
But there is quite a bit of focus shift, especially at close focus, which I think explains the DXO data showing it getting worse as you stop down.
That's a bugger. But other than that it's very nice (except at 35mm). Sharp across the frame from wide open, contrasty, and with surprisingly smooth bokeh in situations where you can see any (i.e. at close focus wide open)
the long end is a bit uncontrasty, and needs stopping down to get sharp. But it's a terrific 16-18-21-24-28 f4...