Convert Leaf MOS to HEIC Online

MOS is the RAW format used by Mamiya Leaf medium-format digital backs - the Aptus, Aptus-II, Credo, and the Mamiya Leaf Credo line that mounted on Mamiya 645DF, Phase One XF, and Hasselblad H bodies. Resolutions run from 22MP (Aptus 22) up to 80MP (Credo 80). Commercial product photographers, automotive shooters, and luxury real-estate teams convert MOS to HEIC for client preview galleries: an 80MP frame that weighs 25MB as a quality JPG lands around 12-15MB as HEIC at the same visual quality, halving gallery load times and iPad storage on set.

Capture One Pro is the de facto MOS processor because Phase One acquired Leaf in 2014 and integrated per-back profiles deeply. The sensible pipeline is to develop in Capture One with lens cast correction applied, export a 16-bit TIFF for the retoucher, and generate HEIC previews for client review. HEIC's 10-bit color support is a genuine advantage at this end of the market: medium-format files are prized for tonal smoothness, and 8-bit JPG previews visibly band on studio backdrops and automotive paint gradients where 10-bit HEIC holds clean.

Client-side, HEIC previews shine in Apple-centric review workflows - art directors approving on iPads, gallery links opened on iPhones - where the format renders natively at half the bandwidth. The limits: PowerPoint on Windows, most web-based proofing platforms, and print bureaus expect JPG or TIFF, and Windows reviewers need the HEVC codec installed. Convert MOS to HEIC for the Apple review loop and keep HEIC to JPG handy for the deliverables that must travel further.

MOS is the long-running medium-format RAW container from Leaf Imaging, founded in 1992 in Israel and acquired by Mamiya, then later folded into Phase One in 2014. MOS files were originally written by Leaf's DCB scanning back in the 1990s and continued through the Aptus and Credo digital-back lines used with Mamiya 645 and Hasselblad V system bodies. Capture One Cultural Heritage remains the reference processor. MOS files are rare today but persist in the heritage-imaging, museum, and high-end product studios where Leaf and Mamiya backs are still working tools.

RAW files are the unprocessed sensor output of a digital camera - 20 to 100 MB each, unviewable without specialist software. Converting RAW to HEIC develops the file into a finished, viewable photo at a small fraction of the size, with automatic white balance and tone mapping applied. Compared with the traditional RAW-to-JPG step, HEIC output is roughly half the size again and supports 10-bit colour, preserving more of the tonal depth the RAW capture contains.

Photographers working in the Apple ecosystem use RAW-to-HEIC to build lightweight browsing libraries: the HEIC versions live in Apple Photos and sync through iCloud for review and sharing, while the RAW masters stay on an external archive. A season of shoots that would occupy hundreds of gigabytes as RAW previews fits comfortably in iCloud as HEIC.

Keep the RAW originals - They remain the editable master with full recovery latitude. And when delivering to clients or platforms whose HEIC support is unknown, convert to JPG instead; HEIC is the right choice for storage and Apple-native workflows, JPG for universal delivery.