Re: FE 16-35mm f/4 ZA field curvature and aperture sweet spots
Fred Miranda wrote: DavidBM wrote: Fred Miranda wrote: trogdon wrote:
Interesting, I've always had the best results around the 18m mark for 35mm as far as edges go. I wonder if the tough E mount adapter being a little thicker causes it to hit the focus a little sooner?
I've noticed at 35mm the autofocus isn't all that reliable for infinity at least on my a7r, but the lens is pretty easy to manual focus so I do that most of the time
I removed the distance settings from my notes as this can be confusing. From my experience, each copy behaves differently and I have tried many 16-35/4 copies. What is surprising on my current 16-35/4 copy is how precise the 'digital' hard stop is which is not the case with other 'focus-by-wire' lenses I have.
After a previous conversation with Fred about the "digital hard stop" I've been doing tests; roughly speaking I'm finding my Batises and FE lenses to have remarkably accurate infinity stops *as long as you stop turning as soon as the infinity sign appears* as your focus from near to far.
Less roughly I've done enough comparisons of the FE 1.4/35 to be sure that focussing on infinity that way is *as or more accurate* than carefully focussing with magnified view. Don't know why I started on that lens, which I almost never use at infinity! Batis 18-25-85 to come....
It works that way with my 16-35/4 and 55/1.8. However, I tested my Batis 85/1.8 and the "digital hard stop" was away off!...
Curses! It seems fine on the B25 and B18, though I need to look more closely....
I wonder if it's just the focal length magnifies the error, or is the error too gross for that?
Apr 13, 2017 at 11:48 PM
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