Compared with the Nikkor 24-120 / 4 VR, the Sigma is a whole shovel harder for haptic very nice. For me there are but three defects: once the often carped 82er filter thread - if the large diameter of at least vignetting would benefit ... but I must admit that I have resigned myself because my Zeiss 18er and 21er, unlike the vast majority of Nikkor lenses have the same thread. Then the fixing of the sun visor: which is so stiff that I'm afraid to feel and zero backlash the lens barrels, if you did it a few dozen times. I zoom for donning and doffing now completely out and hold the inner (outgoing) tube firmly so as not to overburden his leadership. There is much copied in the world, many tripods see eg. same - why not copy the mechanism of Zeiss aperture that easily come off and sit up and rock solid? Thirdly, polarizing filters are with the hood attached not to use. That's when many similar lenses so, but you can easily solve, there are examples.
For optical power: not much different than that of Nikon lenses 24-70 and 24-120 (and 16-35). In the center super, toward the edge significantly weaker. The sharpness in the corners or at the edge of the narrow side is primarily "bottom around" even in Bl. 8 or even 11 is not really convincing. I mean, a bit better than the Nikkor lenses, but I would like it more sharply. Michael Weber describes my problem well in his Renz Sion the Nikkor 16-35 at the D800 (just type in search engine), just as I see the "Universal zoom 24-XXX". A real weakness of Sigma, as described by many reviewers, is the vignetting, the still visible and much worse than the original Nikkor fails even at f / 8 - with the giant filter thread ...
The other day I received with the Sigma some nice pictures, tripod, focused with Live View, the right showed good sharpness across the entire image field. I was amazed when looking at the screen and almost excited ... if, indeed, if I had not forgotten the shooting, nor the set of the previous telephotography 1.2x crop (then instead of 36 "only" 24 MP) of the D810 off , Logically, if you cut off the margins, it gets better. As bad as the involuntary Tip is not, however, because in many cases, ranging from 24 MP Yes: either this box on, or maintenance work in FX and always generously let edge and trim away later. You can do almost better with the 16-35er: I rarely need the 16 mm, but use it to then cut off by the edge of the field of view adequately 18-20 mm come. Is just a stopgap measure.
I keep it? yes I do. The 24-70 is sold, because it is not significantly better and limited in focal length range for the much higher price. The light intensity I do not really need. The Sigma is haptic class, and because of the Zeiss Distagone I even resigned myself to the filter thread 18 and 21 mm. Now the Nikkor 16-35 is (currently, despite deficiencies still irreplaceable) the filter thread break in the city tours backpack ...
The Nikkor 24-120 I will probably sell.
