----- Original Message ----- From: "Rob Studdert"
Subject: RE: FA 20 f2.8
On 7 Dec 2004 at 18:47, Nick Clark wrote:
Was this test done on the *istD? If so that might explain why you didn't see the soft corners.
I'm afraid even the *ist D's crop doesn't help, not with my A20/2.8 in any case.
None of the real wides are great in the corners wide open, I don't think even the Leica Elmarit-R 19/2.8 is profoundly sharp in the corners at f/2.8. It's just life with super wides on SLR cameras. I just got some stuff done with my A15/3.5 which I shot at f/8, and there are no corner sharpness issues with it, though wide open, it isn't good. My A20/2.8 is the same way. Not the sharpest in the corners wide open, but very good down a stop or two, and excellent down another couple of stops.
Something to consider with super wides is how you tend to compose pictures with them. Often, there will be something fairly close in the corners, simply because the angle of view forces it. Even a 20mm is going to have some DOF problems wide open with an object close to the lens and the focus set close to infinity. What may appear to be mushy corners can also be lack of DOF.
William Robb
