Wide Angle Zoom Showdown:
Canon 16-35mm f2.8 L v Nikon 17-35mm f2.8 AFS
Over there are the Nikonians, and over there are the Canonites. And ne'er the twain shall meet. Team Nikon loves its 17-35 and Camp Canon loves its 16-35. Each claims the superiority of its champion but rarely are they tested head to head.
Nikon-EOS adaptors enable the comparison to made easily enough, but in practice is the Nikon good enough to justify the loss of auto focus and the complication of stop down metering?
I suspected that defining 'better' in this instance would be slippery: even the Leica 21-35mm is not equally rectilinear at all focal lengths. Both these lenses have differing distortion characteristics throughout their range, so your verdict will likely be weighted in favour of your preferred FOV - which end of the zoom you use the most.
Further muddying the waters, it seems to be beyond the limits of mass production technology to make a lens this complicated, with such fine tolerances, and to make them all the same. More than any type of lens, wide angle zooms are bedevilled by sample variation - likely you have heard many rumours about 'good' and 'bad' specimens and stories about manufacturers calibrating them back to nominal spec.
Finally, after many months research, trial and (mostly) error, I have in my clutches what I believe to be optimal copies of both lenses.
As previous tests on the 1Ds II have shown beyond doubt, a healthy Nikon 17-35mm AFS is capable of performing at the highest level, rivalling any prime in the 19-21mm range. If yours hasn't impressed you, give it to Nikon for a few weeks; it will when it's recalibrated. I was lucky enough to pick a great one first time.
The Canon 16-35mm also gets a mixed press. Mike Hatam tried six copies before finding an acceptable one. At the time of writing, the rumour mill is grinding out a line about improved QC since the summer; but who knows? In the light of such uncertainty I went straight to the horse's mouth: this sample comes direct from Canon UK on loan and proved to be as good a 16-35mm as I've ever seen or used.
With the playing field as level as can reasonably be hoped, let's consider the tale of the tape...
Continue to Lens Specifications ...
Tests conducted with Canon 5D at ISO50 shot RAW with mirror lock up and processed via Capture One 3.7.3 into 8-bit Adobe RGB, sharpened in PhotoShop (135/0.5/3) and converted for web with BoxTop ProJPEG. All captures manually focus bracketed.