10-22-2014, 04:11 PM
The Sigma was adapted to a Nikon DX (D7000, 16 MP, AA filter) while the NEX7 has 50% more pixels and more modern sensor. It's not directly comparable, I'd say.
The Sigma delivers a far better resolution in the borders at f/5.6 (2155 to 1581) - never look only at the center resolution, no lens should be weak in the center. A difference of only 100 lw/ph is hardly noticeable. Nearly 600 lw/ph are a big difference.
And, of course, 2 ⅓ stops faster DO make a difference, too.
The Sigma delivers a far better resolution in the borders at f/5.6 (2155 to 1581) - never look only at the center resolution, no lens should be weak in the center. A difference of only 100 lw/ph is hardly noticeable. Nearly 600 lw/ph are a big difference.
And, of course, 2 ⅓ stops faster DO make a difference, too.