SonyArwView — Sony A7 V (.ARW) Thumbnails & Preview Viewer for Windows 11

Get File Explorer thumbnails for Sony A7 V (ILCE-7M5) .ARW RAW files — and other recent Sony bodies — and open them in Windows Photos, on Windows 11, without decoding RAW sensor data. SonyArwView surfaces the full-resolution JPEG preview the camera already embeds in every .ARW and hands it to Windows' own JPEG decoder.

It targets recent Sony cameras whose RAW Windows doesn't handle yet — the newer bodies shooting Compressed HQ RAW (A7 V / ILCE-7M5, A1 II, A9 III, …). The extraction is format-general, so it works with any Sony .ARW that embeds a preview. (Built and verified on the Sony A7 V.)

What you get:

• ✅ Explorer thumbnails for .arw — real, upright (orientation-correct) photos
• ✅ Double-click → opens the photo in Windows Photos (the embedded preview), with no command-window flash
• ✅ Or pass it through to your own viewer (FastStone, Lightroom, …) with the original .arw, so you keep full-folder browsing — see Open in your preferred viewer
• ✅ Batch extraction to .jpg via a small console tool
• ✅ Coexists with the Microsoft Raw Image Extension — no need to remove it
• 🚫 No RAW decode. No demosaicing, no LibRaw/ExifTool/ImageMagick/.NET, no network, no services. Native C++17 + MSVC; static-CRT binaries.

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Install

SonyArwView is a small signed app package (MSIX). It is signed with a self-signed certificate, so you trust that certificate once, then install the package. No Developer Mode needed.

Download SonyArwView.msix and SonyArwView.cer from the latest release, then three clicks:

1. Trust the certificate (once): right-click SonyArwView.cer → Install Certificate → Local Machine → Place all certificates in the following store → Trusted People → Finish. (Approve the admin prompt.)
2. Install the app: double-click SonyArwView.msix → Install.
3. Make it the default for .arw: open any .arw, choose SonyArwView — Sony ARW Preview, and tick Always.

That's it. Open a folder with Extra large icons — thumbnails appear — and double-click any .arw to view it in Photos.

(Step 3 is unavoidable: Windows resolves the thumbnail handler from the file's default app and protects that choice, so it can't be set silently.)

Prefer one command? The release also bundles Install.ps1, which does steps 1–2 and opens the Settings page for step 3: powershell -ExecutionPolicy Bypass -File .\Install.ps1

Build from source

Prerequisites (Windows 11 x64):

• Visual Studio 2022 or Build Tools for Visual Studio 2022, with:
  • the MSVC v143 — VS 2022 C++ x64/x86 build tools, and
  • the Windows 11 SDK (10.0.26100) — also provides makeappx/signtool used to build and sign the package.
• CMake ≥ 3.20 (the VS C++ CMake tools component includes it).

Install the Build Tools with exactly those components in one shot:

winget install Microsoft.VisualStudio.2022.BuildTools --override `
  "--quiet --wait --add Microsoft.VisualStudio.Workload.VCTools --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 --add Microsoft.VisualStudio.Component.Windows11SDK.26100 --add Microsoft.VisualStudio.Component.VC.CMake.Project --includeRecommended"

Then build, and (optionally) build + install the package:

cmake -S . -B build -G "Visual Studio 17 2022" -A x64
cmake --build build --config Release

powershell -ExecutionPolicy Bypass -File .\scripts\build-package.ps1  # -> build\installer\SonyArwView.msix
powershell -ExecutionPolicy Bypass -File .\scripts\Install.ps1        # trust cert + install

Uninstall

Remove SonyArwView from Settings ▸ Apps ▸ Installed apps, or run scripts\Uninstall.ps1 (also removes the trusted cert and resets the .arw default).

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Open in your preferred viewer (optional)

By default, double-clicking an .arw extracts the embedded preview and opens it in Windows Photos. If you already have a viewer that reads Sony .arw natively (FastStone, Lightroom, …), you can point SonyArwView at it — double-clicking then launches that viewer with the original file, so you keep full-folder browsing and side-by-side compare. Explorer thumbnails are unaffected either way.

Open SonyArwView from the Start menu to get a small settings window (in English or French, following your Windows display language):

• it shows whether SonyArwView is your .arw default (with a button to fix it), and
• lets you choose Windows Photos or your own viewer (Browse to its .exe).

Power users: the same setting can be scripted with scripts\Set-Viewer.ps1 -Path "...\FSViewer.exe" (or -Clear). It's stored per-user in %USERPROFILE%\.sonyarwview\viewer.txt — a file, not the registry, because the packaged handler runs with a virtualized registry and wouldn't see an HKCU value written from outside the package.

Note: this only helps if your viewer can actually read the camera's RAW. For the newest Compressed HQ RAW that nothing decodes yet, leave it on Windows Photos (the extracted preview).

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Batch-extract previews (no install needed)

$exe = ".\build\src\SonyArwPreviewExtract\Release\SonyArwPreviewExtract.exe"
& $exe DSC00001.ARW preview.jpg     # extract the embedded preview to a JPEG
& $exe --info DSC00001.ARW          # offset, size, dimensions, orientation
& $exe --scan-folder C:\path\to\arw # report every .ARW in a folder

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What's in the box

Component	Kind	Purpose
ArwPreviewExtractor	static lib	Endian-aware TIFF/IFD parser; finds & validates the embedded preview; reads orientation.
SonyArwPreviewExtract.exe	console	Batch extractor (--info / --scan-folder).
SonyArwOpen.exe	windowless	The .arw "open" handler bundled in the package — extract→Photos, or pass-through to your viewer (no console window). Launched with no file (from Start) it shows the settings window.
SonyArwWicDecoder.dll	COM / WIC	Exposes .ARW to classic/desktop WIC apps (optional).
SonyArwThumbnailProvider.dll	COM	Orientation-correct Explorer thumbnails.
SonyArwView (MSIX)	app package	Packages the thumbnail provider so it can win .arw on Win11, and bundles the open handler.
WicDecodeTest / ThumbTest	console	Source-of-truth testers.

src/     ArwPreviewExtractor · SonyArwPreviewExtract · SonyArwOpen · SonyArwWicDecoder
         SonyArwThumbnailProvider · SonyArwThumbnailPackage · WicDecodeTest · ThumbTest
scripts/ build-package · Install · Uninstall · Set-Viewer  (+ advanced register/unregister helpers)
docs/    HOW-IT-WORKS · TROUBLESHOOTING · REGISTRY

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Docs

• How it works & why it's built this way (Windows arbitration, why an MSIX package, the dead-ends) — docs/HOW-IT-WORKS.md
• Troubleshooting (no thumbnails, Photos, conflicts, debug logging) — docs/TROUBLESHOOTING.md
• Registry / system footprint & clean removal — docs/REGISTRY.md

Diagnostic logging is off by default (SONY_ARW_WIC_DEBUG=1 / SONY_ARW_THUMB_DEBUG=1 → %TEMP%).

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Status

Verified end-to-end on Windows 11 x64 against real Sony A7 V samples: 17/17 extract a full-res preview; Explorer shows upright thumbnails; double-click opens the preview in Photos; works alongside the Microsoft Raw Image Extension.