Schneider-Kreuznach LS — fast leaf-shutter medium-format prime for Phase One 645 / Mamiya 645AF
The LS 110mm f/2.8 is a Schneider-Kreuznach leaf-shutter prime built for the Phase One 645 digital platform, sharing the Mamiya 645AF bayonet. It launched with the first LS lens series around 2010, giving studio shooters a fast standard-to-short-telephoto option.
As a leaf-shutter optic it carries its own in-lens shutter rather than a focal-plane shutter, enabling flash sync at all speeds. Autofocus runs internally when paired with a compatible Phase One 645DF-series or Mamiya 645DF body, and the image circle covers medium-format digital backs on that mount.
At f/2.8 on a medium-format sensor the 110mm gives noticeably shallower depth of field than 35mm-format equivalents of similar view, making it a common choice for portrait and studio product work. Full-speed flash sync is a practical edge over longer LS lenses in strobe-lit setups.
Used copies trade mainly among working Phase One and Mamiya 645DF owners, so supply is thinner than for 35mm-format glass. Buyers should test the leaf shutter across its full speed range, check the autofocus coupling for wear, and confirm compatibility with the digital back and firmware.