Re: Sigma 20mm f/1.8 EX DG opinions wanted

[Joseph Tainter]

I have use of one when I want it, and was able to test it 
against an FA 20 f2.8. It was a rigorous test, on a tripod, 
with the subject a mud-brick wall about three meters away 
(we have many such walls here in New Mexico). I shot both at 
f2.8 -- which is wide open for the Pentax but stopped down 
for the Sigma. The Pentax blew away the Sigma. It was 
clearly sharper in the center, at the edges, and in the 
corners. I kept the FA 20 and returned the Sigma to where I 
had borrowed it from. I will never look at Sigma lenses the 
same again.

It is a very useful focal length, but get the FA 20 f2.8.
Joe