Haydon wrote:
Your image above illustrates that sharpness is subjective to the photographer. Everyone has different standards.
Totally agree. I posted the image to give someone an idea of what they can expect from the lens. If its sharp enough for you, you might want to look at the lens. If not, you might want to pass it up. It would be much sharper if taken it with a Nikon 400mm f2.8, which I can't afford at $11,000.
But to be quantitative, this is from the PCmag.com review: "At 18mm f/3.5, the lens delivers strong sharpness from edge to edge. It scores 2,335 lines on Imatest's center-weighted evaluation score, but performance is very good from center (2,423 lines) to edge (2,235 lines). Stopping down to f/5.6 delivers a modest resolution bump (2,457 lines), and the lens delivers excellent results at f/8 (2,862 lines) and f/11 (2,846 lines). We see a slight drop at f/16 (2,389 lines), and a huge one at f/22 (1,492 lines). Diffraction is at fault hereโthe opening of the iris is so mall at f/22 that light scatters and harms image quality significantly. This is true at every tested focal length. ...[article goes through all the zoom factors]... At the 400mm position the chromatic aberration at the periphery of the frame is more visible. And the center resolution takes a couple steps back too. At f/6.3 the lens shows soft results on average, 1,627 lines, with edges that are just 1,256 lines. There's a good jump in the center at f/8, which brings the average up to 2,009 lines, but edges are weak (1,464 lines). Again, depth of field will hide soft edges in many, but not all, photos."
Here's another, just for reference: D7200 and Tamron 18-400mm f3.5-6.3, ISO 800, 1/500 sec, f/6.3, 400mm (600mm 35mm equivalent), handheld.