RAF to ORF Converter

Encoding: the RAF uses uncompressed or lossless compressed sensor data in Fujifilm's own container; ORF uses losslessly compressed sensor data, with a preview and thumbnail, and the download is a Linear DNG: demosaiced 8-bit RGB with the colour matrices raw editors need.

Bit depth: 12 to 16 bits per channel depending on the camera in the RAF; ORF allows 12 bits per channel, and the DNG written here has 8 bits per channel, linearised. The sensor's 12 to 16 bits are not used: the 8-bit camera preview is converted.

Colour: camera RGB from an X-Trans 6×6 or Bayer 2×2 mosaic in the RAF; ORF supports camera RGB from a Bayer mosaic, written here as 8-bit sRGB.

Metadata: the RAF can carry EXIF and Fujifilm maker notes, including the Film Simulation; ORF can carry EXIF and Olympus maker notes, which also contain the preview, but nothing is copied across.

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

ORF is the raw format of Olympus and OM System cameras, built around Four Thirds and Micro Four Thirds sensors. It stores 12-bit sensor data with a JPEG preview kept inside Olympus's maker notes.

ORF looks like TIFF but replaces the version number 42 with the letters 'RO', so a little-endian file starts 'IIRO' and generic TIFF readers reject it. Its JPEG preview is not in the main image directory but inside the camera-settings block of Olympus's maker notes.

ORF files come from Olympus E-series DSLRs, OM-D and PEN mirrorless cameras and OM System bodies.

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

What ORF offers when it comes straight from the camera: Compact files from a smaller Four Thirds sensor; High Res Shot results stored as a single file; Supported across two decades of Olympus and OM System bodies. Its drawbacks: An 'IIRO' header that generic TIFF readers reject; 12-bit depth, less than most full-frame raw files; A preview hidden inside the maker notes.