|
Nikkor AF-S 17-55mm f/2.8 G IF-ED DX - Review / Test Report - Analysis |
|
Lens Reviews -
Nikon / Nikkor (APS-C)
|
|
Page 2 of 2
Distortion
The AF-S 17-55 mm shows a quite typical distortion characteristic for a lens in
this class. At 17mm there is some relatively pronounced barrel distortion
changing to moderate pincushion distortion towards the long end of the zoom
range. At 24mm both forces even out with virtually no distortion at this
focal length.
17mm:
24mm:
35mm:
55mm:
The chart above has a real-world size of about 120x80cm.
Vignetting
The AF-S 17-55mm DX is a reduced image circle lens (APS-C) and typical for
such lenses so vignetting is somewhat more pronounced compared to full frame lenses.
As to be expected the problem is most significant at 17mm @ f/2.8 where the
vignetting exceeds 1.2EV at the image borders. The issue eases towards the
55mm end of the zoom range but vignetting remains relatively high here.
However, from f/4 & up the issue is well under control for such a lens.
MTF (resolution)
As to be expected for a lens in this price class the AF-S 17-55mm DX is a pretty
impressive performer regarding resolution but it is not a lens without flaws.
The center resolution of the lens is extremely high straight from the max. aperture
regardless of the focal length. At medium aperture settings it reaches the resolution
limits of the D200 sensor.
At 17mm the borders as well as the extreme borders are pretty decent even at f/2.8
and very good at medium aperture settings. Unfortunately there's a weak spot at
24mm where the extreme borders are quite soft at f/2.8 but from f/4 and up they
catch up quite nicely. At 35mm the borders are on a pretty high level
straight from f/2.8. Same goes for the 55mm setting though the borders don't
really reach the high levels of the other tested focal lengths anymore.
The lens exhibited a quite high degree of residual spherical aberrations
(focus shift when stopping down) at 24mm as well as strong field curvature at 17mm.
Please note that the MTF results are not directly comparable across the different systems!
Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness.
If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations
Chromatic Aberrations (CAs)
Chromatic aberrations (color shadows at harsh contrast transitions) are relatively
well controlled for such a zoom lens. The issue is a little bit more pronounced
at large aperture settings towards the wide-end of the zoom range (> 1px on the
average at the image borders) where CAs may be visible in some situations.
VerdictThe Nikkor AF-S 17-55mm f/2.8G IF-ED DX is a professional grade lens and it certainly
shows up regarding its exceptionally high build quality as well as very fast AF speed.
Optically it is, without doubt, a very good lens but it has a few issues. The center performance
is nothing short of stellar but the borders are a little worse than desirable at 24mm @ f/2.8 and
at 55mm (for such a lens).
The level of CAs, distortions as well as vignetting is quite typical for a lens in this class
but then thing aren't substantially better either. So all-in-all there may be a few question marks
regarding the price/performance ratio of this lens. It simply lacks the greatness suggested
by its price tag.
|
