Sigma 24-105mm f/4 DG OS HSM | A ("Art") (Canon EOS) - Review / Test Report Lens Reviews - Canon EOS (Full Format) Article Index Introduction Analysis Sample Images & Verdict Tweet Page 1 of 3 Review by Klaus Schroiff, published January 2014 Introduction Lately Sigma had quite a run in delivering very decent products not only in terms of value but also optical & mechanical quality as well as improved quality control. The transformation of their product lineup is still at the beginning but they are busy executing their new product vision. One of their latest products in the Sigma 24-105mm f/4 HSM DG OS | A. As the name implies it is part of the "Art" series thus their most prestigious segment of lenses. In Canon land, it is obviously targeting the Canon EF 24-105mm f/4 USM L IS which has been the 1st choice among customers looking for a high quality, full format standard zoom lenses with a slightly longer reach. Interestingly the Sigma lens is just marginally more affordable than its Canon counterpart. This trend certainly shows that Sigma is getting more confident about its products compared to high end products from original manufacturers. The build quality of the Sigma lens is - although it may still be surprising for some - simply superb. Besides some metal parts, Sigma uses a new material called TSC (Thermally Stable Composite) which contributes to the high quality perception. There's no wobbling whatsoever and that's despite a duo-cam zooming mechanism (two inner lens tubes). The broad zoom and focus rings are nicely rubberized and operated smoothly. It is worth to mention that the lens is rather massive especially when zooming towards the 105mm setting and with attached lens hood. The 24-105mm f/4 HSM DG OS | A features Sigma's ultrasonic AF drive (HSM="Hypersonic") which is similar to Canon's USM both in terms of high speed and negligible noise. Of course, this applies to phase detection AF whereas in Live View mode you shouldn't expect wonders here. Image stabilizers are mainstream theses days and Sigma has implemented their variant (OS="Optical Image Stabilizer") which provides an equivalent gain of around 3 f-stops in real life situations. It is also worth to note that the lens is compatible to Sigma's USB dock (for AF/OS tuning) and they also offer a mount conversion service (e.g. Canon EF to Nikon). Here’s how the specs compare against its primary competitor: Sigma

24-105mm f/4 DG HSM OS | A Canin EF

24-105mm f/4 USM L IS Elements/Groups 19/14 18/13 Special Elements 3x aspherical, 2x SLD, 2x FLD 3x aspherical, 1x UD Image Stabilizer Efficiency 3? f-stops 3 f-stops Aperture blades 9 (circular) 8 (circular) Min. focus (magnification) 0.45m (1:4.6) 0.45m (1:4) AF motor ultrasonic with FTM ultrasonic with FTM Size 89x109mm 84x107mm Weight 885g 670g Filter size 82mm 77mm water/dust protection no yes approx. Price (EUR) ~800€/900$ ~900€/~1050US$



