Sigma reinvented itself in 2012 with a terrific new lens design (I was initially skeptical about the branding) at relatively inexpensive prices, which really seemed to usher in a new competitive era in third-party lenses. Now it's taking it all a step further by getting into the cinema-lens business, hopefully bringing with it the same quality optics. It enters the market with a full set of key lenses, too, rather than just floating a trial balloon of a single lens.
The bulk of the company's Cine lenses -- all but two of the eight -- are designed for use on full-frame cameras like the Canon EOS 5D Mark IV and Sony A7 series rather than the Super 35-sensor-size cameras common in pro recording gear. (Note that Super 35 covers various sensor sizes with different aspect ratios. Sigma uses the 1.8 aspect, or 24.6x13.8mm standard.)
They're broken down into three lines: High Speed Zoom line optimized for Super 35, comprised of an 18-35 mm T2 and 50-100mm T2; FF Zoom line for full frame, which consists of a 24-35mm T2.2; and FF High Speed Prime line, with 20mm, 24mm, 35mm, 50mm and 85mm lenses, all with a maximum T-stop of T1.5.
(As a refresher, an f-stop is the physical size of the aperture that lets light in, while a T-stop is the f-stop corrected for the amount of light that the lens actually transmits to the sensor.)
Note that all the lenses are special versions of the company's core lenses for still photography -- and they weigh significantly more, though don't seem much bigger. They're all weather sealed with glow-in-the-dark markings, 180-degree focus rotation and front mounts for standard-size filters and accessories.
Sigma plans to ship Canon EF and Sony E-mount versions of the two High Zoom lenses by early December for $4,000. PL-mount versions will follow for all but the 24-35mm. The company also roadmaps another zoom and five more primes for 2017. You can find all the specs for the various models on Sigma's site.
Editors' note, October 20, 2016: Updated with price and availability for the two High Zoom lenses.