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Sigma AF 100-300mm f/4 EX DG HSM APO (Nikon) - Review / Test Report - Analysis |
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Lens Reviews -
Nikon / Nikkor (APS-C)
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Page 2 of 3
Distortion
Distortion is exceptionally well controlled with this lens. The Sigma produces only marginal barrel
distortion at 100mm (0.1%) and very slight pincushion distortion (0.4%) at 300mm.
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Move the mouse cursor over the focal length text marks below to observe the respective distortion
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200mm |
300mm |
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Vignetting
Typical for most full format tele lenses the Sigma produces only a marginal degree of vignetting on
APS-C type DSLRs. The issue remains below 0.4EV at all focal length even at wide open aperture.
The situation remains as good when using the lens combined with a Sigma AF 1.4x converter.
MTF (resolution)
The Sigma AF 100-300mm f/4 EX DG HSM APO delivered excellent resolution figures in the MTF lab
matching the best zoom lenses in its range as well as many fix-focal length lenses. At 100mm the
Sigma performed about as good as it gets here with an extremely high center performance and only
marginally worse borders. Following the zoom range towards the longer end there's a slight decrease
in resolution. However, even at 300mm the center resolution remains excellent accompanied by very
good borders straight from f/4 all the way up to f/11.
Combined with the Sigma AF 1.4x EX DG converter there's a drop in performance in the center
but more so towards at the borders. However, the results remain generally on a very good level
although it may be advisable to stop down a little here for an extra kick in terms of contrast.
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 very well controlled in the
native 100-300mm range. The average CA pixel width at the borders varies between extremely
low ~0.2px (100mm) and ~0.8px (@ 300mm). The situation deteriorates when adding the
AF 1.4x EX DG converter resulting in more noticeable CA pixel widths of around 1.1px.
Bokeh
Regarding its relatively moderate max. aperture (f/4) the Sigma may not be the most
interesting candidate for an analysis of the bokeh (the quality of the out-of-focus blur)
but if your subject is close enough the lens can render these image parts quite nicely thanks
to a smooth and uniform blur and decent, circular out-of-focus highlights (at f/4).
At f/5.6 highlights start to show hints of the aperture blade edges though.
You can download the full-size sample images here:
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