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Tokina AF 50-135mm f/2.8 AT-X Pro DX (Nikon) - Review / Lab Test Report - Analysis |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 2
Distortion
The level of distortion is reasonably well controlled for a zoom lens.
At 50mm there is relatively pronounced barrel distortion (~1.2%) changing to a similar degree of
pincushion distortion (~1.1%) at 135mm. At 85mm the two forces even out (~0.4%).
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Move the mouse cursor over the focal length text marks below to observe the respective distortion
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| 50mm |
85mm |
135mm |
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The chart above has a real-world size of about 120x80cm.
Vignetting
The Tokina is a dedicated APS-C lens so the vignetting is a little bit more pronounced at
f/2.8 (~0.4-0.8EV). However, this is still pretty decent for such a kind of lens.
MTF (resolution)
The lens exhibited a very good to exceptional performance in the MTF lab although the
centering quality left something to be desired at 135mm.
At 50mm the resolution is very high throughout all tested aperture settings with an
excellent peak around f/5.6. There is a performance drop at 85mm @ f/2.8 affecting the
image borders (only) but from f/4 onwards the resolution is already very good to excellent
again. As mentioned the tested sample showed a slight centering problem which affected
the border performance at 135mm @ f/2.8 (see the quite different figures in the test
of the Canon variant of this lens). Stopping down lifts the quality to very good
levels again. The focus field of the lens is somewhat curved.
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)
The Tokina produces relatively pronounced lateral CAs (color shadows at
harsh contrast transitions) peaking around 1.1px at 50mm and 1.4px at 135mm f/2.8.
This may be field relevant in critical scenes.
Verdict
The Tokina AF 50-135mm f/2.8 AT-X Pro DX is a very good lens with a few flaws.
The resolution figures are generally very good although a centering problem
limited the potential of the tested sample here (at the long end of the zoom range).
The contrast level is generally very high except at 135mmm f/2.8.
Typical for dedicated APS-C lenses the vignetting is a little more pronounced
at wide-open aperture but all-in-all the issue is still relatively well controlled.
The distortion characteristic is about average whereas lateral chromatic
aberrations are a little high at the extreme ends of the zoom range. The
bokeh, the out-of-focus blur, is generally very smooth and buttery. The
mechanical quality of the lens is absolutely superb and it is a joy to handle
this quality - more of this, please! The Tokina does still rely on the old
slotted drive-screw for AF (which is not present anymore on Nikon budget DSLRs) - this
approach is a bit dated by now although the principal AF performance is very
fine.
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