Fast wide-angle to standard zoom lens for Micro Four Thirds cameras.
The Panasonic Leica DG Vario-Summilux 10-25mm f/1.7 ASPH. is a remarkable constant-aperture wide-zoom for Micro Four Thirds cameras, combining the Leica DG design collaboration, constant f/1.7 brightness throughout the zoom range, and ASPH aspherical elements. The Summilux designation indicates the premium Leica optical pedigree. This lens achieves constant f/1.7 across a 2.5× zoom range — technically challenging.
10–25mm zoom range (20–50mm full-frame equivalent on MFT), f/1.7 constant maximum aperture throughout, ASPH aspherical elements, Micro Four Thirds mount, power OIS, 77mm filter thread.
The constant f/1.7 aperture across the full zoom range is the defining specification — no other standard zoom of similar coverage maintains this brightness. This enables event photography, low-light video, and shallow depth of field across the normal perspective range. Used with power OIS and Panasonic GH-series or Lumix S cameras (via adapter), it is a remarkably versatile standard zoom.
Test that f/1.7 maintains across the full zoom range — this is the lens's key differentiator to verify. Check power OIS function. Inspect elements for haze and condition. Confirm MFT mount engagement. Test AF accuracy and speed on compatible bodies.