MOS to MP4 Converter
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Supports: MOS
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Need help?MOS to MP4 Converter
A MOS file is a medium-format RAW photograph from a Leaf or Mamiya digital back — a single still image, not a video. This converter wraps that one still inside an MP4 video container, producing a short clip that simply holds the photo on screen (with no motion). That makes the image playable in any video player, droppable straight onto a timeline in a slideshow or editor, and embeddable where MP4 is accepted but RAW is not.
What This Conversion Actually Produces
Because MOS holds a frozen frame and MP4 is a motion-video format, the output is a fixed-duration clip showing your single RAW photo — think of it as the photo "held" for a few seconds rather than animated footage. Set how long the still is held with Duration (default 5 seconds per frame), choose what fills any area around the image with Background Color (default Black), and the still is encoded with the H.264 video codec that MP4 uses by default. If you instead want an ordinary picture file, convert MOS to JPG — and if you want to string several photos into a moving slideshow, JPG to MP4 is the better fit.
MOS Format at a Glance
| Property | Value |
|---|---|
| Type | Camera RAW (medium-format digital back) |
| Developer | Leaf / Leaf Imaging (now part of Phase One) |
| Used by | Leaf Aptus series and Mamiya digital backs |
| Container basis | TIFF-based |
| Variants | Uncompressed sensor data, or TIFF with lossless JPEG compression |
| Sensor data | Unprocessed RAW capture |
| Opened by | RawTherapee, Adobe Photoshop, Phase One Capture One, Adobe DNG Converter |
| Best for | Professional studio capture, maximum post-processing latitude |
MP4 Format at a Glance
| Property | Value |
|---|---|
| Standard | ISO/IEC 14496-14 (MPEG-4 Part 14) |
| Type | Video container |
| Default video codec here | H.264 (AVC) |
| Holds | Motion video, audio, subtitles, metadata |
| Native playback | Chrome, Firefox, Edge, Safari, and virtually all hardware players |
| Best for | Universal sharing, web embedding, editor and timeline import |
How to Convert MOS to MP4
- Upload Your MOS File: Drag and drop your
.mosfile or click "+ Add Files". The file is uploaded over an encrypted connection. - Set the Hold Duration: Use Duration to choose how many seconds the still is displayed (default 5 seconds per frame) — this sets the length of the output clip.
- Pick Quality and Background (Optional): Set the Quality Preset (default Very High (Recommended)), choose a Background Color for any letterbox area (default Black), or set a Resolution preset to scale the frame.
- Convert and Download: Click "Convert" and download your MP4. No sign-up, no watermark.
Frequently Asked Questions
Does the MP4 contain any motion or just the still photo?
Just the still. A MOS file is a single RAW photograph, so the MP4 shows that one frame held for the duration you set — there is no animation, panning, or footage to recover, because none exists in the source. It is a way to carry a still inside a video container, not a way to turn a photo into a moving scene.
Why would I convert a RAW photo to MP4 at all?
Two common reasons. First, to drop a hero shot onto a video timeline without exporting an intermediate image — many editors accept MP4 more readily than RAW. Second, to share or embed an image where only video is allowed (some upload fields, players, or feeds). For everyday use, converting MOS to JPG is usually what you want instead.
Will I lose RAW image detail in the MP4?
Some, yes. MOS captures unprocessed high-bit-depth sensor data, while MP4's H.264 codec stores 8-bit video and applies lossy compression, so the deep editing latitude of the RAW file does not survive. Keep the original .mos for archival and editing; treat the MP4 as a delivery copy. Raising the Quality Preset reduces visible compression but cannot restore RAW bit depth.
Can xconvert open compressed MOS files from Leaf backs?
MOS comes in an uncompressed variant and a TIFF-with-lossless-JPEG variant. Note that Adobe Camera Raw historically did not support the compressed MOS and IIQ variants from Leaf cameras, which is why Phase One Capture One or the Leaf Raw Converter are often used for those originals. If a particular MOS file fails to convert, re-exporting it from Capture One as a TIFF or JPEG first is the reliable path.
How do I make a slideshow from several MOS photos instead of one clip per file?
Upload multiple files and choose the Merge images strategy to combine them into a single video, with the Duration setting controlling how long each photo is shown; choose Video per image to get a separate clip per file. For a polished multi-photo sequence we generally recommend converting the photos to JPG first, then using JPG to MP4.
What resolution will the MP4 be?
By default the converter keeps the source dimensions, which for medium-format Leaf and Mamiya backs are large. You can scale the frame down with a Resolution preset if you need a smaller, more web-friendly file. In our testing, holding the source resolution produces a noticeably larger MP4 than a 1080p preset for the same hold duration, since every frame carries the full-resolution still.
Is my MOS file kept on your servers?
No. Your file is uploaded over an encrypted connection, processed on our servers, and the upload and output are deleted automatically a few hours after conversion. No account is required, and there are no watermarks or hidden tiers.