What Is a RAF File? Fujifilm's RAW Format, Explained
A RAF file — say it "raff" — is Fujifilm's RAW format, written by every X-series and GFX body when you shoot RAW. It is not a finished picture. It holds the reading from every photosite on the sensor at the instant of exposure, together with the camera's metadata, your Film Simulation choice and embedded JPEG previews, in a single .RAF file. That makes it your digital negative: the whole photograph, before any decisions about how it should look were locked in.
The RAF format also carries one twist no other brand shares: most X-series bodies use Fujifilm's X-Trans sensor, whose color mosaic is laid out differently from the pattern the rest of the industry uses. First the essentials, then the twist.
RAF at a glance
| Full name | Fujifilm RAW |
|---|---|
| Extension | .RAF |
| Written by | Every Fujifilm X-series body and the GFX medium-format line |
| What it holds | Unprocessed sensor data, EXIF metadata, your Film Simulation setting, embedded JPEG previews |
| Sensor twist | Most X bodies use Fujifilm's X-Trans color mosaic; GFX bodies use a conventional Bayer sensor |
| Compression | Uncompressed on every body; lossless compressed on X-Trans III bodies and later; a lossy compressed option on the newest generation |
| Typical size | Around 85 MB uncompressed or 45 MB lossless compressed on 40 MP bodies like the X-T5; GFX files run far larger |
| Opens with | macOS Preview and Photos, and RAW editors such as RevelRaw, Lightroom or Capture One |
What's actually inside a RAF file
A camera sensor doesn't record a picture. Each photosite records how much light hit it through a single-color filter — red, green or blue — arranged in a mosaic. A RAF file stores those readings as they came off the sensor:
- The mosaic sensor data. One brightness value per photosite. On most X bodies that mosaic is Fujifilm's X-Trans arrangement rather than the usual Bayer pattern. No white balance, no sharpening, no Film Simulation has been applied yet — turning the mosaic into a viewable photograph is the job of your RAW editor.
- Metadata. Camera body, lens, exposure settings, and the Film Simulation you had dialed in — Provia, Velvia, Astia, Classic Chrome. It's recorded, not baked into the pixels, so the look stays a suggestion you can revisit.
- Embedded JPEG previews. The camera develops previews with its own processing — Film Simulation included — and tucks them inside the RAF. That's what you see on the camera's screen and in Finder thumbnails, which is why a RAF can look one way as a thumbnail and another once an editor opens the real data.
Is a RAF file the same as RAW?
RAW is the category; RAF is Fujifilm's member of it. Each camera brand wraps its sensor data in a container of its own design — Sony writes ARW, Nikon writes NEF — and when you set a Fujifilm to shoot RAW, a RAF is what lands on the card. There is no separate "plain RAW" to choose instead. The differences that matter sit one level down, and two of them belong to Fujifilm alone: the X-Trans mosaic and the way Film Simulations travel. Both next.
X-Trans: why the same RAF looks different app to app
Nearly every digital camera arranges its red, green and blue filters in the same repeating Bayer pattern. Fujifilm's X-Trans sensor, fitted to most X-series bodies, arranges them differently. Your editor has to reconstruct full color from that mosaic, and because X-Trans is the rare pattern, editors diverge more on it than they do on Bayer — the same RAF can render crisp in one app and mushy in another, with fine texture like foliage showing the gap first. If you shoot X-series, open a few of your own files in any editor you're considering before you commit. GFX medium-format bodies sit out this story: they use conventional Bayer sensors, just with far bigger files.
Your Film Simulation rides inside the RAF
Shoot JPEG and the camera bakes your Film Simulation — Provia, Velvia, Classic Chrome, Acros — into the pixels. Shoot RAF and the camera writes the same choice into the file as a setting, with the neutral sensor data intact underneath. You can frame a scene in Classic Chrome today and develop the same file as Velvia next year.
The catch: Fujifilm's color recipes live in the camera's processor, so only two things render a simulation exactly as the camera would. The camera itself, at capture. And X RAW Studio, Fujifilm's free desktop app, which sends the RAF back through a USB-connected camera to develop it. Lightroom, Capture One and RevelRaw start from the neutral data with looks of their own — close on a good day, never the camera's pixels. If the in-camera color is the point, shoot RAW+JPEG. If the film look is the point and you want your own hand on it, our guide to the film look from Fujifilm RAW builds it from the RAF up.
Compressed, lossless compressed or uncompressed: which your Mac reads
Fujifilm bodies offer up to three RAW recording settings. Uncompressed writes every bit with no shrinking. Lossless compressed packs the same bits into roughly half the space, the way a ZIP does; nothing is discarded and the photo develops identically. The newest bodies add plain compressed, which trims a little data to get files smaller still. Rough sizes by generation, give or take the scene:
| Bodies | Uncompressed | Lossless compressed |
|---|---|---|
| 26 MP X-Trans 4 (X-T4, X100V, X-Pro3) | ~55 MB | ~28 MB |
| 40 MP X-Trans 5 HR (X-T5, X-H2, X100VI) | ~85 MB | ~45 MB |
| 102 MP GFX (GFX100 II, GFX100S II) | ~200 MB | ~100 MB |
The setting also decides what your Mac does with the file. Apple's built-in decoder reads uncompressed RAF only: set the camera to either compressed flavor and Preview, Photos and Quick Look show a generic icon, even for a body Apple supports. The file is fine; the decoder skips it. Lightroom, Capture One and Fujifilm's own free apps read all three settings. Lossless compressed remains the right call for most shooters — half the card space for nothing lost — as long as a real RAW editor is doing the opening. On a 40 MP body the choice compounds fast; if you're picking that editor for an X-T5, our X-T5 software guide compares the field.
How to open RAF files on a Mac
macOS ships with RAW support for most Fujifilm bodies, so the basics are already on your Mac: Preview opens RAF files with a double-click, and Photos imports them. Three caveats. Apple's decoder wants uncompressed RAF, as covered above. Files from a just-released camera can fail to open until Apple ships a RAW update for that body — the file isn't broken; your software just hasn't met that camera yet. And Preview only shows you a develop of the RAW; it isn't an editor. The fixes, in order, are in our guide to opening RAF files on a Mac, and the Fujifilm page collects every Fuji guide on this site.
To actually develop the file — choose your own white balance, recover highlights, work the color — you need a RAW editor. RevelRaw is built around Sony Alpha, but it opens Fujifilm RAF files all the same — drag one in or pick it from File > Open, and AI scene detection ranks 40+ presets against your photo, with the standard fine-tune controls on top. Everything runs on your Mac; no file ever leaves it. The big subscriptions — Lightroom, Capture One — read RAF as well.
How to convert RAF to JPEG
For a quick conversion with no editing, Preview can do it — uncompressed RAF only: open the file, then File > Export, choose JPEG, and set the quality. For a conversion that's actually developed — your exposure, your color, your take on the Film Simulation — open the file in a RAW editor and export. RevelRaw exports JPEG, PNG, TIFF and HEIF, with platform presets for Instagram, print and web. Either way, keep the RAF afterwards: it's the negative, and every JPEG is just one interpretation of it. Every route, X RAW Studio included, is in our guide to converting RAF to JPEG on a Mac.
FAQ
Which cameras write RAF files?
Every Fujifilm body that shoots RAW — the whole X-series and the GFX medium-format line. The extension never changes; the sensor behind it does: X-Trans on most X bodies, conventional Bayer on GFX.
Why does the same RAF file look different in different editors?
X-Trans arranges its color mosaic differently from every other brand, and each editor reconstructs full color from it in its own way. The quality of that reconstruction varies, so the same file can render differently across apps.
How do I open a RAF file on a Mac?
Double-click it: Preview handles files from most Fujifilm bodies. Files from a just-released camera may need to wait for a macOS RAW update. To develop rather than just view the file, use a RAW editor such as RevelRaw.
What is lossless compressed RAF?
An option on newer bodies that shrinks files to roughly half the size of uncompressed RAF. It's lossless — nothing is discarded, and the photo develops identically. One catch: Apple's built-in decoder skips it, so Preview and Photos only open uncompressed RAF. RAW editors and Fujifilm's free apps read it fine.
Why won't my RAF file open on my Mac?
Check the camera's RAW recording setting first: Apple's decoder reads uncompressed RAF only, so Preview, Photos and Quick Look skip compressed and lossless compressed files. If the files are uncompressed, the camera may be newer than your macOS RAW support — install updates when they arrive, or open the file in a RAW editor or one of Fujifilm's free apps.
Can RevelRaw open RAF files?
Yes. Drag a RAF in and it opens like any other RAW — presets, scene detection and fine-tune controls all work. Exports go out as JPEG, PNG, TIFF or HEIF.
See what's really in your RAF files. Download RevelRaw, drop one in, and watch it ranked against 40+ presets in seconds — with one full-quality export on the house. Get it on the Mac App Store.
Related reading: Fujifilm RAW editing on a Mac · How to open RAF files on a Mac · How to convert RAF to JPEG on a Mac · Best editing software for the Fujifilm X100VI · The film look from Fujifilm RAW · All RAW formats RevelRaw opens · RW2, Panasonic's Lumix RAW · ORF, the Olympus and OM System RAW · What is an ARW file? · What is a NEF file? · What is a CR2 file?