Sigma AF 12-24mm f/4.5-5.6 EX DG HSM - Review / Lab Test Report
Lens Reviews - Nikon / Nikkor (APS-C)
Article Index
Introduction
Analysis

Introduction

The Sigma AF 12-24mm f/4.5-5.6 EX DG HSM is of three ultra-wide zooms made by Sigma - obviously a primarily playing field for the company. The 12-24mm EX is a full format lens and as such it is unique regarding its range. In fact there isn't even a (mass production) rectilinear SLR fix-focal this wide. Quite an achievement! On an APS-C DSLR the specifications are not all that impressive anymore but the field-of-view is still equivalent to a classic 18-36mm lens so even here it keeps its ultra-wide character.

Due to the extreme design Sigma had to choose a very protruding front element so there's no front filter thread by default. However, when attaching the lens cap holder there is a option to mount a filter here (82mm). At 12mm this causes slight edges shading so front filters can only be used from about ~14mm. There's a gelatine filter slot at the rear of the lens (useful for color filters for B&W photography).


Note: The image above shows the Canon variant of the Sigma AF 12-24mm f/4.5-5.6 EX HSM DG

The build quality of the lens is very impressive and among the best of what I've seen from Sigma so far. The typical EX finish (smooth crinkle style) feels very pleasant and the zoom and focus control rings operate very smooth and well damped (focus ring only). It doesn't really matter in this class but the lens has a pretty fast and near silent HSM (hypersonic motor) AF drive with full-time manual focusing in single-shot AF mode.

Specifications
Equiv. focal length18-36 mm (full format equivalent)
Equiv. aperturef/6.8-f/8.4 (full format equivalent, in terms of depth-of-field)
Optical construction16 elements in 12 groups inc.4 SLD and 3 aspherical elements
Number of aperture blades6
min. focus distance0.28 m (max. magnification ratio ~1:7.1)
Dimensions87 x 103 mm
Weight600 g
Filter size82 mm (non-rotating - see issues above)
Hoodbuilt-in, petal-shaped
Other featuresgelatine filter slot




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