OpenAnyFile
What is a .mef file?
Mamiya RAW is a camera RAW format developed by Mamiya. It is usually created by Mamiya ZD.
Produced by Mamiya's medium-format ZD camera and backs in the late 2000s.
File details
| Full name | Mamiya RAW |
|---|---|
| Category | Camera RAW |
| MIME type | image/x-mamiya-mef |
| Developer | Mamiya |
| Opens with | RAW preview extractor |
| Uploaded? | No — read locally in your browser |
How to open a .mef file
OpenAnyFile routes .mef files to its RAW preview extractor, which shows the full-size preview the camera embedded in the file.
- Drop your .mef file on the box above, click it to choose the file, or paste it with Ctrl+V.
- The real format is detected from the file's first bytes — not just its name.
- The file opens in the RAW preview extractor.
- Use fullscreen for a closer look, check its checksums, or download it back unchanged.
What works — and what does not
Works
Viewing and inspecting: the full-size preview the camera embedded in the file. Size, type, signature and checksums are always shown.
Does not work
Editing layers or the raw data. You see the preview image stored in the file, not an editable document.
Is it safe to open a .mef file online?
Here, yes — because nothing is uploaded. Most "online viewers" send your file to their server. OpenAnyFile reads it with your browser's File API and decodes it on your own device, so there is no copy anywhere else. You can check: open your browser's network tab while opening a file — no upload appears.
Questions about .mef files
Can I open a .mef file without installing software?
Yes. OpenAnyFile opens .mef files in your browser using its RAW preview extractor. You get the full-size preview the camera embedded in the file, with nothing installed and no account.
How do I know a file is really a .mef file?
Check its first bytes instead of its name. This format has no fixed signature, so the detected type and the readable content are the best clues. OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .mef file uploaded anywhere?
No. The file is read locally by your browser and never sent to a server — it even works offline once the page has loaded.
Does it work on phones?
Yes — on Android and iPhone, in any modern browser. You can also install OpenAnyFile as an app.
Related formats
Other formats from the same family:
Format facts checked and page updated on September 25, 2026.