Sigma AF 70mm f/2.8 EX DG macro - Full Format Lab Test / Review
Lens Reviews - Canon EOS (Full Format)
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Introduction
Analysis

Review by Klaus Schroiff, published November 2010

Lens kindly provided for testing purposes by Christoph Siegwart!

Introduction

The Sigma AF 70mm f/2.8 EX DG macro is the 5th and latest of the current macro lenses made by Sigma. The focal length of 70mm is a bit off the mainstream but it can make sense if you'd also like to use it e.g. for portrait photography. Another interesting aspect of the lens is the optical design. Unlike most other moderate macro lenses it uses 3 SLD elements to correct optical flaws. This ambitious approach has one obvious side effect - the lens is quite a bit more expensive than the 50mm f/2.8 macro and roughly on par here with ~100mm macro lenses. Size- and weight-wise it is also more comparable to its longer cousin.

The 70mm f/2.8 is part of Sigma's professional grade EX ("Excellence") lineup and consequently the build quality is very good thanks to high quality materials and quite tight tolerances. The focus ring operates pretty smooth. Unfortunately it rotates in AF mode which is a slightly dated behavior on Canon DSLRs. As you can see below the Sigma extends quite a bit towards close focus distances. The metal lens hood is of the screw-in type which is a bit unusual but you can continue to use a polarizer with attached hood. The front element does not rotate.

The Sigma has a conventional AF micro-motor which is very slow and quite noisy. Unless you use the lens for macro photography it is a good idea to take advantage of the focus limiter in order to avoid excessive AF hunting. The AF accuracy of the tested sample was generally very good.

Specifications
Optical construction10 elements in 9 groups inc. 3 SLD elements
Number of aperture blades9
min. focus distance0.257 m (max. magnification ratio 1:1, ~6.5cm min. working distance)
Dimensions76 x 95 mm
Weight525 g
Filter size62 mm (non-rotating)
HoodBarrel shaped, screw-in type, supplied
Other featuresfocus limiter




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