Hi--

>> >I also have a Sigma 18-35mm but I beg to differ from the above
>> >findings. I have shot a fair number of indoor group photos with it at
>> >18mm, f8 (and also stopped down futher). A number of the photographs
>> >show so much distortion at the edges that people in the group
>> >photographs at the edge looks like they have gain an instant 50 pounds -
>> >I mean the face are flatten, widen and stretched. Nevertheless, the
>> >Sigma is still a very beautiful and sharp lens, provided I avoided the
>> >wider focal lengths for group shots.

>> I think you may be confusing two image characteristics, linear distortion,
>> and perspective characteristics... You can find more on these subjects
>> on my web page under "I babble", then "On Seeing and Perspective", and
>> "On Lens Distortion Types". BTW, I would have a hard time believing that
>> the Sigma 18-35 has low linear distortion at 18mm - but, oddly enough,
>> high linear distortion of the "barrel" type would actually reduce the
>> "distortion" you refer to...

>Thanks for pointing that out for me. I just have one question. From
>what I understand from your explanation, having a prime lense would not
>solve my problem of 'stretched' faces. Is my assumption correct?
>Please let me know because I am seriously considering getting prime
>lenses to correct this distortion I have. If prime lenses would not
>help, I have to reconsider my options.
> Alan Chung alchung@pc.jaring.my

If the zoom shows a smooth curvature of subject straight out away from the
photo center (you can't judge this in most SLR viewfinders, which have the
reverse distortion), then the zoom would actually be better for people than
a good prime, which would likely have less linear distortion. My favorite
lens for super-wide coverage (while being kind to people) is the 16mm
fisheye on a 1.4X converter (The last B & W photo on my web page, under
"AHT Photoz" was shot with this - notice also that building verticals
remain roughly vertical, even though the camera is tilted [another good
aspect of spherical perspective...]. You may also want to read "On Seeing
and Perspective", under "I babble"...). Good primes may give you improved
sharpness, though...