Why does the same RAF file look different in different editors?

Most X-series bodies use Fujifilm's X-Trans sensor, whose color-filter mosaic is arranged differently from the Bayer pattern every other brand uses. Each editor has to work out full color from that mosaic its own way, so how good an X-Trans photo looks depends noticeably on how well the editor handles it — and the same RAF can render differently from one app to the next.

What Is a RAF File? Fujifilm's RAW Format, Explained

Q: Which cameras write RAF files?

Every Fujifilm body that shoots RAW writes .RAF — the whole X-series and the GFX medium-format line alike. The extension never changes; what changes is the sensor behind it: most X bodies use Fujifilm's X-Trans mosaic, while GFX bodies use a conventional Bayer sensor.

Q: How do I open a RAF file on a Mac?

macOS has built-in RAW support for most Fujifilm bodies, so Preview and Photos open RAF files directly. Files from a just-released camera can fail until Apple ships an update. To actually develop the file rather than just view it, use a RAW editor — RevelRaw opens RAF files with drag and drop on any Mac.

Q: What is lossless compressed RAF?

An option on newer Fujifilm bodies that packs the same sensor data into a file roughly half the size of an uncompressed RAF. Because the compression is lossless, nothing is discarded — the photo develops identically; the file just takes less room on the card.

Q: Can RevelRaw open RAF files?

Yes. 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 every preset, AI scene detection and fine-tune control works on it. Exports go out as JPEG, PNG, TIFF or HEIF.

Published July 24, 2026 · Daniel Tello · RevelRaw

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.

RAF 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	Newer bodies offer lossless compressed RAF, roughly half the size of uncompressed
Typical size	Roughly 30–90 MB on 26–40 MP X bodies depending on compression; 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.

X-Trans: why RAF is a little different

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 — so how good an X-Trans photo looks depends noticeably on the editor, and the same RAF can render differently from one app to the next. If you shoot X-series, it's worth opening a few of your own files in any editor you're considering. GFX medium-format bodies sit out this story: they use conventional Bayer sensors, just with far bigger files.

The other thing worth knowing: your Film Simulations survive in the RAF. The JPEG bakes the look in; the RAF records it in metadata and keeps the sensor data underneath, so you can shoot Classic Chrome today and change your mind next year. And if your camera offers lossless compressed RAF, use it freely — roughly half the size, nothing discarded.

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. Two caveats. First, 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. Second, Preview only shows you a develop of the RAW; it isn't an editor.

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: open the RAF, 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.

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 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.

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.