Just unpacked the replacement copy of the Tokina 16-28. I'll check for centering immediately.
Also: will get a second sample of the Sigma 85/1.4 next week and see if it behaves like the first one.
-- Markus
Editor
opticallimits.com
[quote name='IanCD' timestamp='1298742939' post='6381']
With Nikon at the other end of your QC scale, maybe the 12-24 looks an (expensive) better bet?
[/quote]
Well, umm... I've used two Nikon 12-24s so far. Neither exhibited really good centering quality.
[quote name='BG_Home' timestamp='1298845139' post='6390']
Well, umm... I've used two Nikon 12-24s so far. Neither exhibited really good centering quality.
[/quote]
Similar experience here with the Nikkor 17-55/2.8.
-- Markus
Editor
opticallimits.com
[quote name='mst' timestamp='1298837855' post='6389']
Just unpacked the replacement copy of the Tokina 16-28. I'll check for centering immediately.
[/quote]
Better, but still not good. Good enough for a lab test (where I can work around the issue somewhat), however I won't do any field tests with it.
-- Markus
Editor
opticallimits.com
[quote name='mst' timestamp='1298845583' post='6391']
Similar experience here with the Nikkor 17-55/2.8.
-- Markus
[/quote]
Well, to sound a little more positive, my unsatisfactory N70-200 VR2 is my first bad Nikkor
Between my wife and myself we've had 12 good ones over the years
That's it - It's the 13th That's the reason!!
I was not aware of the second effect - interesting. With global loss of contrast you mean that the whole image frame is affected evenly? If so, it is really hard to check because one would need a second lens to compare the contrast levels. Low contrast alone could just be a normal "feature" of the lens.
[quote name='Klaus' timestamp='1298732900' post='6380']
That's one potential effect - one or more elements are more or less centered (the center is where it should be) but tilted.
The other one is a more a global loss of contrast caused by an off-center (shifted) element and that's harder to check in shops.
[/quote]
[quote name='BG_Home' timestamp='1298845139' post='6390']
Well, umm... I've used two Nikon 12-24s so far. Neither exhibited really good centering quality.
[/quote]
While searching for the "perfect" walk-around lens three years ago I had to test three exemplars of the 16-85 VR. Each of them had a different weakness. At the end I kept the lens which mostly suited the anticipated usage (more at the wide end than at the tele end).
At the moment I mainly use a Sony A850. Here, my walk-around lens is a Tamron 28-75. My exemplar has clearly a tilted focus plane at the tele end. However, I am tired of the lens selection game and accept it like it is for now.
[quote name='mst' timestamp='1298845583' post='6391']
Similar experience here with the Nikkor 17-55/2.8.
[/quote]
Interesting. So I'm not alone on that one, too. Does yours focus properly (front/backfocus)?
[quote name='BG_Home' timestamp='1298930523' post='6406']
Interesting. So I'm not alone on that one, too. Does yours focus properly (front/backfocus)?
[/quote]
Sorry, Basil, but I currently don't own one.
-- Markus
Editor
opticallimits.com
[quote name='mst' timestamp='1298930676' post='6407']
Sorry, Basil, but I currently don't own one.
[/quote]
Alright, no problem.
