On Mon, 17 Mar 2003 18:08:24 -0000, "Bhup" <nospam@nospam.com> wrote:

>Only if you mount the camera on a good tripod. have a lens hood

>then its generally 2 stops from your max. depends on lens

>I only know of one lens which breaks this rule the Nikon 180mm AFn ED this

>one seems sharp wide open

The "two stops from maximum" is so rarely true, it should

have disappeared as a valid "rule of thumb" LONG ago...

For 35mm lenses, "f5.6-8" is more commonly true, but there

are a FEW exceptions on the wider side, and many on the

smaller (especially with super-wides and zooms, for the

image corners). BTW, many good lenses are sharp wide-open,

but their sharpest stop center-to-corner still is around

f5.6-8...