Summary: The Sigma 18-35mm F1.8 DC HSM is an extraordinary lens, offering prime-level image quality in the fastest zoom ever made for SLRs. Its 28-50mm equivalent range is a little limiting though, and inconsistent autofocus means that it can be difficult to make the most of the excellent optics when shooting at large apertures.
Pros: Super fast constant F1.8 maximum aperture, Excellent optics, even wide open, Fast, silent autofocus, Solid build quality without being over-heavy, Compatible with Sigma's USB dock and Optimization Pro software
Cons: Restricted zoom range, Needs detailed AF microadjustment for best results, Inconsistent autofocus in difficult conditions even after microadjustment, Physically rather large for a standard zoom
Excerpt: The word "groundbreaking" seems inadequate for describing the awesomeness of the Sigma 18-35mm f/1.8 DC HSM Art Lens. The primary reason for that awesomeness is the not-seen-in-any-other-zoom-lens f/1.8 aperture. In fact, f/1.8 is 1 1/3 stops wider/faster than the next-widest/fastest f/2.8 zoom lens crowd – allowing more than twice as much light to reach the camera sensor than the tied-for-second place lenses.
Sigma 18-35mm f/1.8 DC HSM | A ("Art") - Review / Test Report
14 May 2014
Conclusion: A few years back we used to *sigh* when a Sigma lens found its way into our labs. However, these days are gone really. Nowadays we are usually wondering in how far Sigma is going to embarrass the competition once more and the Sigma 18-35mm f/1.8 DC HSM | A ("Art" Series) was no exception here. Given its specs it was undoubtedly one of the few surprising releases lately. The primary value prop is, of course, the ultra large aperture.
Excerpt: This much anticipated standard zoom lens for APS-C format cameras sports a fast f/1.8 maximum aperture throughout the zoom range and silent internal focusing with full time manual override. We have a final pre-production sample to test here and it will be available to fit Canon, Nikon and Sigma cameras, with a recommended retail price of £799.
Pros: Excellent sharpness, Constant f/1.8 aperture, Low falloff for an f/1.8 lens, Good build quality, Reasonably priced