Panasonic has revealed full details of its Leica DG Vario-Summilux 10-25mm f/1.7 ASPH. lens.

The optic, which is said to be the world’s fastest constant-aperture f/1.7 wide-angle zoom, is compatible with the company’s G-series cameras like the G9, in addition to other Micro Four Thirds models, rather than its new full-frame S1 and S1R bodies.

Panasonic first announced the development of the lens back at last year’s Photokina event in September, and the official unveiling follows leaks of the specs and images.

From the press release:

Panasonic is proud to introduce a new standard zoom digital interchangeable lens, the LEICA DG VARIO-SUMMILUX 10-25mm / F1.7 ASPH.
(H-X1025), which boasts a large F1.7 aperture throughout the entire 20-50mm (35mm camera equivalent) zoom range and exceptionally high optical performance, clearing the stringent LEICA standards. The LEICA DG VARIO-SUMMILUX 10-25mm / F1.7 ASPH. is suitable not only for stills shooting, but also for video recording, to satisfy both professional photographers and videographers.

The full-range F1.7 ASPH. high-speed aperture provides beautiful bokeh and high descriptiveness. Covering a focusing distance from wide angle to standard zoom range, the LEICA DG VARIO-SUMMILUX 10-25mm / F1.7 ASPH. functions as a multiple fixed focal-length lens, providing the same or higher level of descriptiveness than a fixed focal-length lens can offer. It is suitable for a variety of daily shooting situations, from dynamic landscapes to portraits–even in low-lit scenes– eliminating the need to change lenses between variations in environment.

Comprising 17 elements in 12 groups, the lens system features three aspherical lenses and four ED (Extra-low Dispersion) lenses that effectively suppress the axial chromatic aberration and chromatic aberration of magnification. Spherical aberration and distortion are also corrected by the aspherical lenses for stunningly high resolution. The use of aspherical lenses coupled with the optimum design of the lens system, results in a compact size and light weight, while maintaining its outstanding optical performance.

Compatibility with a maximum 240-fps high-speed sensor drive realizes high-speed and high-precision auto focusing. Notably, the new lens excels in video recording performance. In addition to the silent operation achieved by the inner focus drive system, the stepless aperture ring and micro-step drive system in the aperture control section help the camera smoothly catch up to brightness changes when zooming or panning. The optical design achieves exceptional barycentric stability to minimize image shifts during zooming. Adoption of a focus clutch mechanism enables instant AF/MF switching and accurate manual focusing. The LEICA DG VARIO-SUMMILUX 10-25mm / F1.7 ASPH. also excels in video recording performance with a mechanism that suppresses focus breathing, which was previously a fatal problem of all interchangeable lenses designed for still image photography.

The rugged dust/splash-resistant design withstands use under harsh conditions even at -10 degrees Centigrade for high mobility. Nine blades give the aperture a rounded shape that produces an attractively smooth defocus effect in out-of-focus areas when shooting at larger aperture settings. Filter diameter is in 77mm. A highly reliable metal mount endures long time use.
Panasonic is committed to expanding the of Micro Four Thirds lineup through its LUMIX G series of cameras and lenses.

Panasonic has set a retail price of $1,799.99 for the lens in the and it should be available from July 15.

More info on Panasonic website.