MOS to TIFF Converter

MOS to TIFF Converter

A .mos file is the RAW capture from a Leaf Aptus medium-format digital back — proprietary sensor data built on the TIFF container that generic viewers can't render. TIFF (.tif / .tiff) is the publishing and print industry's standard still-image format. Converting MOS to TIFF renders the RAW into a finished, broadly editable image that opens in Photoshop, InDesign, and any print workflow — the natural handoff once a studio frame is ready to retouch, place, or archive. If you only need to compare facts, this page also has a .tif twin; the formats are identical.

MOS Format at a Glance

TIFF Format at a Glance

How to Convert MOS to TIFF

1. Upload Your MOS File: Drag and drop your Leaf .mos files onto the page or click "+ Add Files". You can queue several Aptus or Aptus-II captures at once, though each medium-format RAW can run from tens to over a hundred megabytes.
2. Set the Compression Type: Open Advanced Options and choose "Compression Type". The default is "JPEG", which is lossy — for a lossless, archival-grade TIFF pick "LZW", "DEFLATE", or "NONE" instead. "LZW" is the standard, broadly compatible choice for a print-ready TIFF.
3. Choose Quality and Resolution (Optional): Leave "Quality Preset" at "Very High (Recommended)" to keep fine studio detail, and keep "Image resolution" on "Keep original" to preserve the back's full pixel count; pick a Preset Resolution or enter a Width only if you need a smaller file.
4. Convert and Download: Click "Convert" and download your TIFF. No sign-up, no watermark.

Frequently Asked Questions

Does converting MOS to TIFF keep the RAW editing latitude?

No — and that distinction matters for a medium-format file. A MOS stores unprocessed sensor data, which is why you can recover highlights and reset white balance in a RAW editor long after the shot. To write a TIFF, the converter renders the RAW first: it demosaics the sensor data and bakes in white balance, exposure, and tone. The result is a high-quality, finished image ideal for retouching and print, but the deep RAW latitude is gone once rendered. Keep your original .mos as the editable master in Capture One and treat the TIFF as the print-and-archive deliverable.

Why is the default compression set to JPEG, and should I change it?

The "Compression Type" dropdown defaults to "JPEG", which applies lossy compression inside the TIFF container — fine for a smaller proof, but not what most people want from a TIFF. For a true lossless, archival-grade file choose "LZW", "DEFLATE", or "NONE". LZW and Deflate both compress losslessly (Deflate usually a little smaller), while "NONE" stores the image uncompressed for maximum compatibility at the largest size. For a medium-format print master, LZW is the safe, widely supported default.

Is MOS the same as the IIQ files from Phase One and Leaf Credo backs?

No. .mos is the Leaf Aptus format specifically. The later Leaf Credo backs — like Phase One's own backs — write .iiq files instead, using Phase One's Intelligent Image Quality compression. They come from the same medium-format world and share a compatibility caveat (the compressed variants can be unreadable in some editors), but they are separate formats. If your file is actually an IIQ, it needs the matching converter, not this one.

Which TIFF does this output, and does it preserve metadata?

It writes a standard TIFF 6.0 file — the same baseline supported by Photoshop, Lightroom, InDesign, and print RIPs. TIFF is a flexible container that can carry rich metadata and multiple color spaces (RGB and CMYK among them), which is part of why it's the print industry's archival choice. The converter renders your Leaf RAW into that container; the TIFF then opens in any professional image or layout application without a RAW-aware plugin.

Why convert to TIFF instead of JPG for a medium-format frame?

It depends on the destination. TIFF is the right call for retouching, print, and archival because LZW or Deflate compression is lossless — every edit and re-save keeps full fidelity, which an 8-bit lossy JPG cannot promise. JPG is the right call when you need to share or view the shot anywhere, since TIFF has essentially no web-browser support (Safari only) and produces much larger files. Many studios keep a TIFF master and export a MOS to JPG copy for delivery, or a MOS to AVIF version for a modern web portfolio.

My MOS file won't decode — what should I try?

MOS comes in uncompressed and lossless-compressed variants, and support for the compressed form varies by RAW processor — even Adobe Camera Raw historically can't read compressed MOS (or IIQ) files. If a file is refused, open the .mos in Capture One, re-save it uncompressed or export an interim TIFF, and convert that. Genuinely corrupted or partially-written backups can't be rescued by any converter; re-copy from the original card or backup if a file won't load.

How big are the TIFFs, and how are my files handled?

In our testing, a full-resolution Leaf MOS written as an LZW TIFF lands close to the size of the rendered image — typically large, because lossless TIFF doesn't shrink a high-megapixel medium-format frame the way a lossy format would; uncompressed ("NONE") is larger still. Your file is uploaded over an encrypted connection, rendered and written to TIFF on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. The main practical limit is upload size and time, since medium-format MOS files often run from tens to over a hundred megabytes each. If a TIFF is larger than you need, run it through the Image Compressor.