NEF is Nikon's in-camera RAW
NEF is the raw sensor data a Nikon camera writes at the moment of capture. It's produced by the camera's own hardware and firmware — software can read it, but nothing can manufacture a genuine NEF from a finished BMP.
Looking to turn a BMP into a NEF file? Here's the honest answer — and what actually works instead.
You can't convert BMP to NEF. NEF is a camera's own RAW format — it only ever comes out of the camera.
NEF is the raw sensor data a Nikon camera writes at the moment of capture. It's produced by the camera's own hardware and firmware — software can read it, but nothing can manufacture a genuine NEF from a finished BMP.
Your BMP is a developed, final image. The extra sensor information a NEF carries — wider dynamic range, full color depth, untouched highlights — was discarded when the photo was first saved, and can't be put back.
NEF is proprietary to Nikon. Even other RAW formats (NEF, ARW, RAF…) aren't interchangeable with it — there is no universal "save as RAW" that produces a real NEF.
Every real RAW file is one of these camera-maker-specific formats, written by the camera itself:
BMP is an uncompressed raster format that stores pixel data with no quality loss, producing large files. It is common on Windows.
How to open BMP opens in most image viewers and editors on Windows and Mac.
Full BMP format guideNEF is Nikon’s raw photo format, preserving all sensor data so you can adjust exposure and white balance without quality loss.
How to open NEF opens in Nikon NX Studio, Lightroom, Photoshop and most raw editors.
Full NEF format guideLossless and uncompressed — ideal for editing, archiving and print.
BMP → TIFFLossless with transparency — perfect for graphics, logos and screenshots.
BMP → PNGA small, universal photo format that opens everywhere.
BMP → JPGConvert your NEF and other camera RAW files to JPG, PNG or TIFF.
Open the converter