twh@geog.pdx.edu wrote in message <6es8en$oel$1@nnrp1.dejanews.com>...
>I recently used a Sigma 70-300 APO zoom lens for some photos of downtown
>buildings. I do not expect perfection in architectural photography using 35mm
>and any zoom, but I found the pincushion distortion at the long end of the
>zoom to be noticeably extreme. I have not had this problem with a Nikon 28-85
>zoom. I've read reviews of other zoom lenses and all mention distortion
>problems for "critical" applications. Is less distortion too much to expect
>from any long zoom? Or is it a problem of 70-300 being too great a focal
>length range? Or would more expensive equipment possibly solve the problem?
>Looking for feedback from those who have had more success. Thanks.

If you are looking for a low-distortion tele zoom, take a look at the
Nikkor 100-300mm f5.6 - it is unusual in that it has almost no distortion
from about 135mm through 300mm, with moderate barrel distortion at 100mm.
Also, the 75-150mm f3.5 E-series zoom on the Nikkor TC200/201 converter
is passably sharp stopped down some, and the combination also has virtually
no distortion.

--
David Ruether
http://www.fcinet.com/ruether
ruether@fcinet.com