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Nikkor AF 24-85mm f/2.8-4 D IF - Review / Test Report - Analysis |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 2
Distortion
The AF 24-85mm f/2.8-4D shows the typical distortion characteristic of a standard zoom lens
with rather pronounced barrel distortion at 24mm (2.55%) changing to moderate pincushion
distortion (0.8%) at the long end of the zoom range. At 40mm distortion is marginal.
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Move the mouse cursor over the focal length text marks below to observe the respective distortion
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| 24mm |
40mm |
85mm |
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The chart above has a real-world size of about 120x80cm.
Vignetting
The AF 24-85mm f/2.8-4D is a full frame lens so it can take advantage of a sweet spot effect
on an APS-C DSLR. Vignetting is very well controlled indeed with about 0.5EV at wide-open
aperture at 24mm and even less at the other focal lengths and aperture settings.
MTF (resolution)
The lens showed an impressive resolution characteristic on the Nikon D200. At 24mm and
40mm the center performance is excellent straight from the max. aperture and the borders
follow quite closely on a very good level. At medium aperture setting the border quality
is also excellent. There´s a decrease in quality at 85mm but the resolution figures
remain very good except at f/4 where the border quality drops to good levels.
The sweet spot of the lens is obviously at the wide-end of the zoom range.
Generally the contrast level is somewhat reduced at large aperture settings, specifically at 85mm.
The lens exhibits quite a bit of field curvature at 24mm which eases when zooming towards
longer focal lengths.
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)
Lateral CAs (color shadows at harsh contrast transitions) are much better controlled compared
to its smaller cousin, the AF-S 24-85mm ED. The situation is "worst" at 24mm but
with an average CA pixel width of around 1.2px at the image borders the Nikkor is
among the best lenses at this setting. Nonetheless CAs can be visible here. The situation
remains roughly comparable at 40mm whereas the CAs decrease to moderate levels at 85mm.
Verdict
The Nikkor AF 24-85mm f/2.8-4D IF is an very good standard zoom and it was
the right decision by Nikon to discontinue its younger cousin (AF-S 24-85mm f/3.5-4.5G IF-ED)
rather than this lens. The resolution characteristics is very good to excellent throughout
the zoom range with a sweet spot towards the wide end. The contrast suffers somewhat at
large aperture settings, specifically at 85mm, but is lifted significantly when stopping
down a little. Vignetting and CAs are very well controlled whereas distortions are about average
for a lens in this class. The mechanical quality is decent without reaching the true
pro grade Nikkors here due to a rather extensive use of plastics and an old style AF.
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