"Alfred Molon" wrote:
In article 8cgfk.74718$kx.60067@pd7urf3no, Dauphin de Viennois says...

All the books on photography I have ever read say you should not use any
lense at its largest aperature setting or smallest due to light
difraction.

Diffraction only occurs at small apertures

Right.

and there are lenses which perform well even wide open.

But they tend to be slow primes, not fast 5x zooms.

http://a.img-dpreview.com/gallery/so...s/dsc00563.jpg

The lower left corner is mush and has CA (red/magenta on the
inner side of edges) to boot. And then there's the upper left...

And don't look at the (CA on the) yellow/orange flowers in the mid-left of
this one.

http://a.img-dpreview.com/gallery/so...s/dsc00575.jpg

--
David J. Littleboy
Tokyo, Japan