RAW to DNG Converter

Encoding: the RAW uses uncompressed, lossless JPEG or vendor-specific coding of the sensor data, depending on the maker; DNG uses lossless (or lossy) JPEG-compressed sensor data, plus optional JPEG previews, 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 in the RAW; DNG allows 8 to 16 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 camera's 8-bit preview is converted.

Colour: camera-native RGB from a colour filter mosaic in the RAW; DNG supports camera RGB plus the colour matrices that map it to XYZ (demosaiced linear RGB in a Linear DNG), written here as 8-bit sRGB.

Metadata: the RAW can carry EXIF and vendor maker notes, almost always with an embedded JPEG preview; DNG can carry EXIF, XMP and DNG tags for colour matrices, calibration and lens corrections, but nothing is copied across.

Camera RAW files (CR2, CR3, NEF, ARW, DNG, ORF, RW2, RAF and others) hold the unprocessed sensor data from a camera along with an embedded full-size JPEG preview rendered by the camera.

.RAW is an extension rather than one format. Panasonic and Leica compacts wrote TIFF-like .RAW files before Panasonic moved to RW2, and scanners and scientific cameras use .raw for headerless dumps with no width, height or layout recorded, which nothing can read without being told those values.

RAW files usually come from older Panasonic and Leica compacts that saved .RAW, and scanners or scientific cameras that use the extension for pixel dumps.

DNG is Adobe's openly documented raw format. Some cameras and phones record it directly, Adobe DNG Converter turns other brands' raw files into it, and a Linear DNG holds already-demosaiced RGB that raw editors treat like any other raw file.

DNG is built on TIFF/EP. The raw image sits in a sub-IFD marked as the main image, with tags for black and white levels, colour matrices and the colour filter pattern; a Linear DNG (PhotometricInterpretation 34892) stores demosaiced RGB instead of a mosaic. Previews are optional, and Adobe DNG Converter can write a medium (1024 px), full-size or no preview.

DNG is the better choice for raw editing and archiving raw files in an open format, while RAW suits editing in Lightroom, Capture One or darktable.

DNG strengths: Open specification read by every raw editor; Lossless compression and optional previews; Recorded directly by Leica, Pentax, DJI drones and phones. Drawbacks to weigh: Large files; No browser or ordinary photo viewer support on every platform.