Excerpt: The well-built Sigma 10-20mm f/3.5 EX DC HSM Lens, at review time, is one of only a few lenses in the ultra-wide angle APS-C lens class to have a fixed maximum aperture. While f/3.5 is not what I typically consider wide/fast, the fixed maximum aperture allows a constant wide open aperture exposure setting to be maintained over the full focal length range of the lens.
Excerpt: Sigma's widest nonfisheye and fastest ultrawide zoom, the constant-aperture 10-20mm f/3.5 belongs to the EX family of sturdily built, optically gifted Sigmas. To control multiple forms of aberration, it uses three low-dispersion glass elements and four aspheric elements-the most of any Sigma. A 15-30mm equivalent on most DSLRs, it joins Sigma's slower and less expensive 10-20mm f/4-5.6 EX ($480, street), which stays in the lineup.
Conclusion: Sigma 10-20 mm f/3.5 turned out to be better than its predecessor in many serious aspects. We have really good speed now – in this category Sigma is only beaten by Tokina 11-16 mm f/2.8. Most of all, however, was corrected the behavior at the edge of the frame, which was the Achilles’ heel of the older model. The performance at the center of the frame wasn’t forgotten, either. The MTF values recorded now place Sigma in the very lead of this equipment class.
Cons: large chromatic aberration in the middle of focal lengths,, quite large distortion at the shortest focal length,, very large vignetting,, noticeable coma.
Conclusion: This Sigma wide-angle comes in at a very reasonable price for what it is and for its features. It's also available for plenty of lens mounts. This lens is considered by some photographers as the benchmark for APS-C wide-angles, though our tests suggest this may not now be the case. But with very little distortion this remains an attractive lens, especially for the price.
Sigma AF 10-20mm f/3.5 EX DC HSM - Review / Test Report
25 July 2009
Conclusion: The new Sigma 10-20 mm f/3.5 EX DC HSM leaves us with mixed feelings. The build quality of the lens is certainly excellent, distortion is a little high at the wide end (but excellent for the rest of the zoom range), there's also a fair amount of vignetting and CA, but that's typical for this lens class. Resolution in the center is excellent, borders also are nothing to complain about and corner performance is ok at 15 and 20 mm, but very disappointing at 10 mm.
Excerpt: Av: Torger Skurve Spesifikasjoner Optisk konstruksjon 13 elementer i 10 grupper. 4 asfæriske, 1SLD, 1ELD Blender blad 7 Minimum fokusdistanse 24cm (1:6.6) Størrelse 88,2x87.3mm Vekt 520g Filter 82mm Solblender Medfølger. Annet Beregnet for crop kameraer Sigma 10-20 f3.5 er storebroren til det velkjente og populære Sigma AF 10-20mm f/4-5.6 EX DC HSM. På papiret så ligger hovedforskjellen i at det er mer lyssterk og at det har en fast blender i hele zoom området.