Merge MOS to PDF

How to Merge MOS Files into a PDF Online

1. Upload Your MOS Files: Click "+ Add Files" or drag and drop multiple Leaf or Mamiya RAW captures. Batch upload is supported, and you can re-order pages by dragging thumbnails before merging.
2. Pick Combine Mode: Default is "Single PDF" — every MOS becomes one page in one combined document. Switch to "Individual PDFs" to output one PDF per MOS file (useful when each frame goes to a different client folder).
3. Set Page Layout, Paper Size, Placement & Margin (Optional): Page layout offers Portrait (default) or Landscape. Paper size includes A4 (default), Letter, Legal, Tabloid, Ledger, A3, ARCH A/B, ISO B4/B5, or "Original" to match each MOS's native aspect. Image placement is Cover (fill page, may crop) or Contained (fit within margins). Image alignment sets Top, Center, or Bottom. Margin presets run from "No margin (0")" through Narrow (0.5"), Moderate (0.75x1"), Normal (1"), and Large (2x1").
4. Tune Compression & Transparency, Then Merge: Image Compression has a Quality Percentage slider (1-100, default 75) for embedded JPEG quality. Compression Type covers Screen (smallest), Ebook, Default, Prepress, and Printer (highest). Image Transparency stays Unchanged unless you pick Removed. Click Merge — files process in your browser session, no sign-up, no watermark.

Why Merge MOS to PDF?

MOS is the proprietary RAW format from Leaf digital backs (Aptus, Aptus-II, Credo) and from Mamiya medium-format bodies that share the same imaging pipeline — Leaf became a Phase One brand in 2009, and Mamiya was acquired the same year. The format is TIFF-based per the raw image format references, so a single capture from a 56-megapixel Aptus or 80-megapixel Credo back can land between 50 MB and 120 MB on disk. Native MOS isn't viewable in browsers, Preview, or Windows Photos at full quality without Capture One, Adobe Camera Raw, RawTherapee, or Darktable — which is fine for the photographer but a problem the moment a client, art director, or print bureau needs to see the take.

Rendering the take to a single PDF solves four practical problems at once: it embeds the demosaiced JPEG so any device can open it, it preserves your sequence order for storyboard or layout review, it lets you fix the page size to A4 or US Letter for predictable on-screen scrolling, and it keeps file size manageable for email or shared drives. Common scenarios:

• Client proof sheets and contact prints — Drop a day's selects into one PDF at Ebook compression and email a 5-15 MB review document instead of asking the client to install Capture One.
• Fashion and editorial portfolios — Use Cover placement with No margin and Landscape layout to fill each page edge-to-edge, then export at Prepress compression for retina-grade portfolio review.
• Fine-art print bureau handoffs — Printer compression keeps the embedded JPEG near visually lossless so the bureau can reference the merged PDF alongside your TIFF deliverables.
• Studio archives and tearsheets — Combine selects from a campaign across multiple Aptus or Credo shoots into one searchable archive PDF you can drop in Lightroom Library or Notion.
• Insurance and provenance documentation — Fine-art photographers document conservation records by merging back-side and front-side MOS captures into a single dated PDF for collectors and galleries.
• Workshop and teaching critique — Send students a paginated PDF of the day's MOS selects so they can mark them up in any PDF reader without needing a RAW workflow installed.

MOS vs Common Image Formats

PDF Compression Type Quick Guide

These presets correspond to the standard Ghostscript PDF settings used by most server-side PDF toolchains, so a Prepress export here behaves the same way as Prepress in Capture One's PDF contact sheet output.

Frequently Asked Questions

Which Leaf and Mamiya cameras produce MOS files?

Leaf Aptus (5, 6, 7, 10, 17, 22, 65, 75, 75s), Aptus-II (5, 6, 7, 8, 10, 12), Credo (40, 50, 60, 80), and Mamiya bodies that ship with Leaf imaging (DM, ZD, 645DF/DF+ mated to a Leaf back). Phase One IIQ files use a different header even though they share the TIFF lineage — point those at our IIQ-aware tools rather than the MOS pipeline.

Will the merged PDF preserve full RAW headroom for editing?

No, and that's true of every MOS-to-PDF tool. PDF stores demosaiced raster data, not sensor RAW, so the merged file is for review, sharing, and print — not for re-editing. Keep your original .mos archive, render the PDF for distribution, and re-export from the RAW any time you need to color-grade.

Why is my merged PDF much smaller than the source MOS files?

Because PDF embeds a demosaiced and JPEG-compressed render of each frame, not the sensor data. A 90 MB MOS captured at 60 MP can become a 4-12 MB page at Ebook compression and 15-30 MB at Prepress. If you need closer-to-original fidelity, drop Quality Percentage to 95+ and pick the Printer preset.

Should I pick Cover or Contained for portfolio review?

Cover scales the image to fill the page and crops if the aspect ratios don't match — best when you want edge-to-edge gallery feel and you're matching paper aspect to your shoot orientation. Contained fits the entire frame inside the margins with no cropping — best for proof sheets where every captured pixel must be visible to the client.

What paper size should I pick if a client is reviewing on screen?

A4 (default) or Letter both work, but if you specifically want a 16:9 monitor-shaped page with no letterboxing, choose "SCREEN_SIZE" from the Paper size dropdown — it produces a landscape page tuned to typical laptop and external display aspect ratios, eliminating the white bands you'd see on A4 in landscape.

Can I merge MOS files captured on different Leaf backs in one PDF?

Yes. The merge engine normalises each MOS to a common embedded JPEG before placing it on the page, so you can mix Aptus 22 (22 MP), Aptus-II 10 (56 MP), and Credo 80 (80 MP) frames in one document. The output PDF will scale each frame to the chosen paper size — pixel-resolution differences won't break the layout.

Do you keep my MOS files after the merge?

Files process in your browser session and are removed automatically after processing — see the xconvert privacy policy. For commercial-confidential RAW captures (unreleased editorial, NDA fashion), this avoids the persistent cloud storage and account-linked logging that Capture One Live or Phase One Capture Pilot bring along.

Can I export individual photos to JPEG or TIFF instead of PDF?

Yes — use MOS to JPG for compressed deliverables or MOS to TIFF for retoucher hand-off. If you already have JPEGs and want to bundle them into a contact sheet, merge JPG to PDF uses the same layout controls described above.

Why won't Adobe Acrobat or Preview open my MOS file directly?

MOS is a proprietary RAW container — Acrobat, Preview, Windows Photos, and most PDF viewers only handle demosaiced raster (JPEG, TIFF, PNG, HEIC) or vector content. To view a MOS, you need a RAW-aware app: Capture One, Lightroom Classic, Adobe Camera Raw (via Photoshop), Adobe DNG Converter, RawTherapee, or Darktable. Merging to PDF here is the simplest way to get a MOS into a viewer that requires no RAW plugin.