Sigma AF 70-200mm f/2.8 EX DG HSM APO - Review / Lab Test Report - Analysis
Lens Reviews - Canon EOS (APS-C)
Article Index
Introduction
Analysis

Distortion

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.

70mm:

200mm:

200mm:

The chart above has a real-world size of about 120x80cm.

Vignetting

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.

MTF (resolution)

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 Imatest Explanations

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.

Verdict

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.

Optical Quality:    
Mechanical Quality:
Price/Performance:discontinued
      
   What does this mean ?



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