The incredibly specified Sigma 18-35mm F/1.8 DC HSM lens, the world’s brightest zoom, has been analyzed by DxOMark. This makes it even more impressive as it scores very highly and even holds its own against bright high-end primes from Sigma and other manufacturers.
This bright wide-angle to normal zoom lens offers a useful range with a wide constant maximum aperture, previously only possible with prime lenses. The sharpness of the Sigma 18-35mm F/1.8 is exceptional even from wide-open. At wide-angle performance is stellar and it drops a little bit towards the telephoto end. Stopping down gains back sharpness quickly. While vignetting is high at bright apertures, no one expects any better given the unique specifications of this lens. Plus, vignetting is the least destructive artifact to correct by software.
Sigma makes this unique lens for 5 mounts: Canon EF-S, Nikon F, Pentax K, Sony A and Sigma’s own S-mount. Just in case you have not guessed from the focal-length, this is an APS-C only lens. It currently sells for $799 USD. Some mounts are expected to ship by the end of this month while the Canon and Nikon versions are already available.