NEF to DNG Converter

Encoding: the NEF uses uncompressed, lossless compressed, lossy compressed, or High Efficiency on recent Z bodies; 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 or 14 bits per channel in the NEF; DNG allows 8 to 16 bits per channel, and the DNG written here has 8 bits per channel, linearised. The sensor's 12 or 14 bits are not used: the 8-bit camera preview is converted.

Colour: camera RGB from a Bayer mosaic in the NEF; 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 NEF can carry EXIF and Nikon maker notes, partly encrypted, plus a thumbnail and a larger preview; DNG can carry EXIF, XMP and DNG tags for colour matrices, calibration and lens corrections, but nothing is copied across.

NEF is the raw format of Nikon cameras, from the D1 to the current Z series. It stores 12 or 14-bit sensor data, uncompressed or compressed, with a JPEG preview the camera renders using its Picture Control.

NEF is TIFF-based: the first directory usually holds a small thumbnail, and sub-directories hold the sensor data and, on current bodies, a full-size JPEG preview. Nikon's maker notes are a TIFF structure of their own, and since the D2X their white-balance block is encrypted with a key derived from the camera's serial number and shutter count.

NEF files usually come from Nikon DSLRs (D-series) and Z-series mirrorless cameras.

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 NEF suits editing Nikon photos in a raw developer.

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.