World's fastest standard zoom — constant f/1.7 Leica DG for Micro Four Thirds across 20-50mm equiv.
The Leica DG Vario-Summilux 10-25mm f/1.7 ASPH is an extraordinary constant f/1.7 zoom for Micro Four Thirds, covering a 20-50mm equivalent range. This is the world's fastest standard zoom lens, providing the speed of a fast prime across the entire zoom range — an achievement no other manufacturer has matched at this aperture.
Optical quality is outstanding with Leica-certified optics delivering sharp, contrasty images with beautiful bokeh throughout the zoom range. The constant f/1.7 enables genuine shallow depth-of-field control at any focal length, making this lens uniquely versatile for both stills photographers and videographers who demand creative background blur.
Build quality is professional-grade with weather sealing and robust construction. The de-clicked aperture ring enables smooth iris transitions for video work. The micro-step aperture motor provides virtually silent operation during filming. The lens is substantial for a Micro Four Thirds optic but justified by the extreme optical specification.
On the used market, the Vario-Summilux 10-25mm f/1.7 offers a lens with no direct equivalent in any camera system. For MFT professionals, videographers, and photographers who want the speed of a prime across a useful zoom range, it provides a genuinely unique capability that eliminates the compromise between zoom flexibility and fast aperture.