Fujifilm RAF MIME Type
image/x-fujifilm-raf identifies, how Fujifilm RAF raw photos are structured, which applications open them, and how Poly handles them. MIME type details for image/x-fujifilm-raf
In active use| MIME type | image/x-fujifilm-raf |
|---|---|
| Extensions | .raf |
| Magic number | 46 55 4A 49 46 49 4C 4D 43 43 44 2D 52 41 57 20 |
| First standardized | 2002 |
| Created by | Fujifilm |
| Browser support | |
| Example applications | FUJIFILM X RAW STUDIO, Adobe Camera Raw |
| Poly support | Yes. Poly organizes Fujifilm RAF photos with thumbnails, previews, metadata, visual search, and agent understanding. |
| Indexed by Poly | Yes. RAF photos are searchable by name, available camera metadata, color, and visual similarity. |
| Preview in Poly | Yes. RAF photos open in Poly's image viewer, with fast thumbnails throughout the app. |
| Poly agent | Yes. The Poly agent can view and reason about the photo's visible content. |
What does image/x-fujifilm-raf mean?
The image/x-fujifilm-raf media type identifies Fujifilm RAW photographs, normally stored with the .raf extension. A RAF file keeps camera sensor data and capture metadata so a raw processor can choose the demosaicing, white balance, exposure, color rendering, noise reduction, and sharpening used for the finished image. Fujifilm describes RAF as its original raw format and continues to use it across X Series and GFX cameras.1
image/x-fujifilm-raf is a conventional identifier, not an IANA registration. It is absent from IANA's image media-type registry. Some software instead uses image/x-fuji-raf, including libopenraw's format documentation.23 Neither spelling defines a formal, public RAF standard.
How is a RAF file identified?
Classic RAF files begin with the 16-byte ASCII signature FUJIFILMCCD-RAW , including the final space. In hexadecimal, that is:
46 55 4A 49 46 49 4C 4D 43 43 44 2D 52 41 57 20
libopenraw documents a big-endian header and offset directory following that signature. The directory points to a JPEG preview, a metadata container, and the color-filter-array sensor data.3 ExifTool likewise describes RAF as a proprietary Fujifilm structure with RAF metadata plus Exif stored in an embedded JPEG preview.4
That layout explains why a file browser can show a RAF photograph without performing a raw development. It can decode the camera-rendered JPEG and leave the sensor samples untouched. A dedicated raw processor instead interprets the sensor layout and camera profile to make its own rendering, which may look different from the preview.
.raf does not create raw sensor data, and renaming a RAF to .jpg does not make it a JPEG.When did Fujifilm introduce RAF?
Fujifilm's FinePix S2 Pro established the recognizable RAF workflow in 2002. Fujifilm announced the camera in May 2002 with a 12-bit CCD RAW recording mode and a converter that could produce 16-bit TIFF files.5 Adobe's camera-support table identifies the S2 Pro's raw extension as RAF.6
RAF has evolved without changing its familiar extension. Current files can contain uncompressed, lossless-compressed, or lossy-compressed raw data, and some specialized modes place more than one raw image in a RAF container. ExifTool records distinct RAF compression values, while Adobe documents HDR RAF as a multi-image format.47
How to open a .raf file
Use software that supports the camera model and its recording mode:
- FUJIFILM X RAW STUDIO sends development work to a connected compatible camera's image processor. This can reproduce the camera's tonality, color, and noise-reduction choices, but it requires a supported camera connection.8
- RAW FILE CONVERTER EX powered by SILKYPIX develops RAF files on the computer and supports Fujifilm Film Simulations.9
- Adobe Camera Raw and Lightroom support many Fujifilm cameras. Adobe lists the minimum plug-in or application version for each model.10
- Apple Photos and Preview-based workflows can use system RAW support for the Fujifilm models and compression modes Apple lists.11
Chrome, Edge, Firefox, Opera, and Safari do not natively develop RAF as a web image. MDN's web image-format guide does not include RAF among browser image formats.12 Publish a rendered JPEG, WebP, AVIF, or PNG for display, and offer the RAF separately when people need the original. Browser-based services may accept RAF uploads, but that is server or application decoding rather than built-in browser support.
Support in Poly
Poly gives RAF photos the same fluid browsing experience as other supported images:
- Sharp thumbnails and an in-app image preview.
- Search by filename, available camera metadata, color, and visual similarity.
- Visual understanding in the Poly agent.
The preview is designed for browsing and visual understanding. For exposure recovery, white-balance changes, demosaicing choices, or multi-image HDR development, use a dedicated RAF editor. Words photographed inside a RAF image are not indexed as text.
Converting RAF for sharing or editing
Raw conversion is a development step, not a filename change. Choose the output for the next use:
| Destination | Best for | Important tradeoff |
|---|---|---|
| JPEG | Email, galleries, and broad compatibility | Lossy and usually 8-bit; much of the raw editing latitude is gone |
| TIFF | High-quality interchange and further editing | Large; stores one rendered interpretation |
| DNG | A raw-oriented workflow in compatible software | Conversion changes the container and camera-specific behavior needs validation |
| PNG | Lossless sharing of a finished rendering | Does not preserve the original raw-development workflow |
Keep the original RAF after export. A rendered derivative cannot recreate all of the sensor measurements later. Take extra care with HDR RAF: Adobe warns that DNG conversion discards every raw image except the first unless the original RAF is embedded.7
RAF files may include detailed Exif and Fujifilm MakerNote data such as timestamps, camera and lens information, shooting settings, ratings, and serial identifiers.4 Review metadata before sharing an original. Also check the export because a derivative may retain more metadata than expected.
Is RAF the same as a Fujifilm JPEG?
No. A RAF may contain an embedded JPEG preview, but that preview is only one component of the file.
| Property | RAF | Fujifilm JPEG |
|---|---|---|
| Usual extension | .raf | .jpg or .jpeg |
| Main purpose | Raw development and preservation of sensor data | Finished image for viewing and sharing |
| Rendering decisions | Chosen later by raw software | Applied by the camera |
| Browser display | Requires conversion or application support | Native in current browsers |
| Editing latitude | High | Lower after camera processing and lossy encoding |
Shooting RAW+JPEG creates two useful files: the RAF master and a camera-finished JPEG. Extracting or displaying the JPEG inside a RAF does not replace a full raw conversion.
Footnotes
- Fujifilm. GFX100 System Brochure. Lists 14-bit and 16-bit RAW recording in Fujifilm's original RAF format. ↩
- Internet Assigned Numbers Authority. Media Types Registry. The image registry contains neither RAF identifier. ↩
- libopenraw. Fujifilm RAF. Documents
image/x-fuji-raf, the identifying string, directory layout, embedded JPEG, metadata, and raw-data region. ↩ ↩2 - ExifTool. Fujifilm Tags. Documents RAF metadata, the embedded JPEG's Exif information, and RAF compression values. ↩ ↩2 ↩3
- Fujifilm. FinePix S2 Pro Launch. Dated May 30, 2002, and describes 12-bit CCD RAW recording and TIFF conversion. ↩
- Adobe. Cameras Supported by Camera Raw. Lists RAF as the raw extension for the FinePix S2 Pro. ↩
- Adobe. Fujifilm HDR RAF Support. Documents multi-image RAF behavior and the DNG conversion limitation. ↩ ↩2
- Fujifilm. FUJIFILM X RAW STUDIO. ↩
- Fujifilm. RAW FILE CONVERTER EX powered by SILKYPIX. ↩
- Adobe. Cameras Supported by Camera Raw. ↩
- Apple Support. Digital Camera RAW Formats Supported by Apple Operating Systems. ↩
- MDN Web Docs. Image File Type and Format Guide. ↩