Sigma AF 70-200mm f/2.8 EX DG HSM APO - Review / Lab Test Report - Analysis
Lens Reviews -
Canon EOS (APS-C)
Thursday, 27 December 2007 01:18
Page 2 of 2
The level of distortion is low for a zoom lens with slight barrel distortion at 70mm changing to slight
pincushion distortion at 135mm and 200mm.
The chart above has a real-world size of about 120x80cm.
Vignetting is very well controlled with the lens - at least on an APS-C DSLR.
At 70mm and 135mm @ f/2.8 vignetting is already well below disturbing levels and hardly detectable
anymore at f/4. At the long end it's more pronounced wide-open with ~0.5EV but even that
shouldn't be a problem in all but the most critical scenes.
The Sigma AF 70-200mm f/2.8 EX DG HSM exhibited a very good to excellent resolution performance
in the lab. At 70mm and 135mm the lens is already very good at f/2.8 increasing to excellent
results at medium aperture settings. At 200mm there's a performance drop at wide-open
aperture where the results are only good. Stopping down helps to lift the quality to an
excellent center and very good borders at f/5.6.
It is worth to mention that the lens suffered from a slight centering problem.
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
Chromatic Aberrations (CAs)
The lens showed an very good behavior regarding chromatic aberrations (color shadows at
harsh light transitions) peaking at about 0.7 pixels at 135mm f/2.8 and below 0.5 pixels
at other settings. By most standards this is nothing to worry about.
The Sigma AF 70-200mm f/2.8 EX DG HSM APO proved to be a worthy although not stellar
representative of its league with quite high performance figures in most categories. At 70mm and 135mm
easily matched and even excelled the Canon EF 70-200mm f/2.8 USM L whereas it was somewhat
worse at 200mm except at medium aperture settings. Both distortions as well as vignetting are
nothing to worry about. The build quality is very impressive. The lens has been discontinued
in the meanwhile.