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HDR to RAF Converter

Convert HDR to RAF in your browser. You download a Linear DNG (.dng), not a .raf: only a Fujifilm camera can create a genuine RAF, and every editor that opens RAF also opens DNG. Nothing is uploaded.

  • Processed locally
  • No upload, no wait
  • No sign-up
  • No watermark

Drop images here

or choose files · paste with Ctrl/⌘ V

HDR expected · other image formats also work

Files are processed on this device. Nothing is uploaded.0 B uploaded

How to use HDR to RAF

  1. 1

    Add your HDR files: drop them here, choose them, or paste from the clipboard.

  2. 2

    There is nothing to tune: the DNG is written uncompressed. Resizing and rotating are under More options if you need them.

  3. 3

    Click Convert. Each file is decoded and encoded in a background thread on this device.

  4. 4

    Download the .dng files one at a time or together as a ZIP.

Why use Aback Images for hdr to raf

Where a RAF would go

RAF files are opened by Fujifilm X RAW Studio, Lightroom, Photoshop Camera Raw, Capture One and darktable, and every one of them opens the DNG too.

DNG next to HDR

The DNG is written uncompressed, so expect it to be several times larger than the HDR, which stores run-length encoded RGBE scanlines.

Written without a lossy pass

The DNG is written uncompressed, so the pixels decoded from the HDR arrive unchanged, apart from precision beyond 8 bits per channel.

Processed on your device

Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.

HDR vs RAF

What changes from HDR to RAF

Encoding: the HDR uses run-length encoded RGBE scanlines; RAF uses uncompressed or lossless compressed sensor data in Fujifilm's own container, and the download is a Linear DNG: demosaiced 8-bit RGB with the colour matrices raw editors need.

Bit depth: an 8-bit mantissa per channel sharing an 8-bit exponent (RGBE), 32 bits per pixel in the HDR; RAF allows 12 to 16 bits per channel depending on the camera, and the DNG written here has 8 bits per channel, linearised. The high dynamic range is mapped to 8 bits per channel, and values above white clip.

Colour: linear RGB (or XYZ in the XYZE variant) in the HDR; RAF supports camera RGB from an X-Trans 6×6 or Bayer 2×2 mosaic, written here as 8-bit sRGB.

Metadata: the HDR can carry a text header with FORMAT, EXPOSURE and optional comments; RAF can carry EXIF and Fujifilm maker notes, including the Film Simulation, but nothing is copied across.

About HDR

Radiance .hdr stores high dynamic range light values, widely used for 3D environment maps and HDRI lighting.

A Radiance file starts with '#?RADIANCE' (or '#?RGBE'), text lines such as FORMAT=32-bit_rle_rgbe and EXPOSURE, a blank line, a resolution line like '-Y 2048 +X 4096', then the scanlines.

HDR files usually come from HDRI environment maps, 360° panoramas and lighting simulation.

About RAF

RAF is the raw format of Fujifilm cameras, from the X series to the medium-format GFX. Most X-series bodies use an X-Trans sensor with a 6×6 colour filter pattern instead of the usual Bayer 2×2.

RAF is not TIFF at the top level: it opens with the text 'FUJIFILMCCD-RAW', then a header with the camera model and offsets to three blocks: a JPEG preview near the start of the file, a header describing the sensor layout, and the sensor data.

RAF files come from Fujifilm X-T, X-H, X-S, X-E, X100 and GFX cameras.

When converting HDR to RAF makes sense

Forms and workflows that ask for RAF usually feed a raw editor, and each of those opens DNG as well, so the DNG can take the RAF's place. Keep the HDR if you only need to view or share the picture.

What RAF offers when it comes straight from the camera: Film Simulation baked into the embedded JPEG; Lossless compressed option on recent bodies; Large medium-format files from GFX cameras. Its drawbacks: Fujifilm's own container rather than TIFF; X-Trans demosaicing differs between raw editors; Film Simulations need camera-matching profiles in third-party editors.

Limitations

  • Light values above 1.0 are clipped rather than tone-mapped, so the sun and bright sky turn flat white.
  • Environment maps are 2:1 equirectangular panoramas, so the picture looks stretched near the top and bottom, as it should.
  • Files in the XYZE variant cannot be read here; RGBE files, the common kind, can.
  • The DNG holds the decoded 8-bit pixels, so it adds no dynamic range or detail beyond the HDR.

Frequently asked questions

Why do I get a .dng file instead of a .raf?

A real RAF is written by Fujifilm cameras and holds the sensor's own readings (12 to 16 bits per channel depending on the camera, stored as uncompressed or lossless compressed sensor data in Fujifilm's own container) along with EXIF and Fujifilm maker notes, including the Film Simulation. An HDR holds no sensor data, so no software outside the camera can create a genuine RAF. The Linear DNG you get instead is Adobe's open raw format, and every editor that opens RAF files opens it with the same raw controls. It holds decoded pixels, so it adds no quality or dynamic range.

Does converting HDR to RAF lose quality?

DNG is written uncompressed, so the pixels are stored exactly as decoded. The high dynamic range is mapped to 8 bits per channel, and values above white clip.

Are my images uploaded anywhere?

No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.

Can I process many files at once?

Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.

Is it free? Is there a file limit or watermark?

It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.