In article <4rsapn$t6@news.esslink.com>, andywlms@esslink.com says...
>In <4rkil4$fng@newsstand.cit.cornell.edu>, d_ruether@hotmail.com (Bob Neuman) >writes:
>>In article <4rk257$bev@newsstand.cit.cornell.edu>, d_ruether@hotmail.com says...
>>>Don't worry about () apertures with super-wides - you do not use them,
>>>if you care about image quality, and super-wides can be hand-held
>>>successfully at absurdly slow shutter speeds [...]
>>
>>Duh, I fergot th' "wide" in th' ferst lyn abuv.....;-)

>I don't quite understand this. I am a fan of superwides and own the
>Sigma 14mm f3.5 and Sigma 8mm f4. I routinely stop these down to
>f8 for optimal sharpness.

That's what I was saying (or trying to ;-): wide apertures are not used
with super-wides if you care about image quality. F8 (or SMALLER) is
required for good edge/corner sharpness, even with the best of them.
It is not very important if the maximum aperture is f2.8 or f5.6,
since using the widest apertures of most super-wides should be avoided
(the only exception I can think of is the 16mm f3.5 Nikkor fisheye,
which is very good at f3.5 and excellent to the corners by f5.6).
Hope This Helps