On Sun, 03 Nov 2002 03:42:05 -0000, Bill Tuthill wrote:
>Neuman - Ruether wrote:

>> I was not impressed with the performance of the
>> 28-70 f2.8 or 28-80 f2.8 Tokinas wider than f5.6
>> (they were soft wider) - at f5.6 and smaller, they
>> were quite good - but that's not the point of buying
>> speed zooms, and many slower lenses perform as well
>> stopped down to f5.6...).

>The Photodo.com MTF graphs agree with you concerning the
>28-70/2.6-2.8 wide open, although it is better at 28mm
>than it is at the two other points tested (40 and 70mm).

This is what I found with the 28-80, too...

>However the Pop Photo SQF charts showed the 28-80/2.8 to be
>excellent wide open at 28 and 80mm, just not in the middle
>(they tested at 50, where 20x enlargements were F quality).

It may depend on test distance and film - at infinity
and f2.8, with the sample I tried, with color slide
film viewed at 5X and 10X, the 28-80 f2.8 Tokina was good
at 28mm over most of the frame, but with soft corners -
though not "crisp"; at 50mm, it was soft throughout; at
80mm, it was VERY bad. On color negatives, it looked
pretty good throughout at f2.8 shooting distant
buildings, though a bit "diffuse" on the trees (more at
the long end than the short...).
In the past, with Nikkors, I found that some WAs would
look sharper in the corners with slide film than with
B&W negative film, but the differing results (with
the slides looking worse) with the Tokina were
surprising. The lens was sharp throughout at f5.6
on both negative and positive films, but unacceptable
at f2.8 except maybe at 28mm on slide film... Other
Tokinas I've tried in the past were very distance-
sensitive for sharpness - maybe this one was better
at distances others used for testing...(?)