NEF to ORF Converter
Convert NEF to ORF in your browser. You download a Linear DNG (.dng), not a .orf: only an Olympus camera can create a genuine ORF, and every editor that opens ORF also opens DNG. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
RAW expected · other image formats also work
How to use NEF to ORF
- 1
Add your NEF files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the DNG is written uncompressed. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .dng files one at a time or together as a ZIP.
Why use Aback Images for nef to orf
Where a ORF would go
ORF files are opened by OM Workspace, Lightroom, Photoshop Camera Raw, Capture One and RawTherapee, and every one of them opens the DNG too.
DNG next to NEF
The DNG stores the camera preview's pixels uncompressed, so it can be as large as the 20 to 60 MB raw file, or larger, depending on the preview's resolution.
No new artefacts
The preview inside the NEF is a camera JPEG; the DNG stores its decoded pixels uncompressed, so this step adds no compression damage of its own.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
NEF vs ORF
What changes from NEF to ORF
Encoding: the NEF uses uncompressed, lossless compressed, lossy compressed, or High Efficiency on recent Z bodies; 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 or 14 bits per channel in the NEF; ORF allows 12 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; ORF supports camera RGB from a Bayer mosaic, 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; ORF can carry EXIF and Olympus maker notes, which also contain the preview, but nothing is copied across.
About NEF
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.
About ORF
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.
When converting NEF to ORF makes sense
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 NEF 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.
Limitations
- The largest embedded JPEG is converted; older bodies sometimes stored only a reduced preview, which then sets the output size.
- Nikon's lossy compressed NEF mode discards some sensor data in camera; the preview used here is not affected.
- The DNG holds the decoded 8-bit pixels, so it adds no dynamic range or detail beyond the NEF.
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Frequently asked questions
Why do I get a .dng file instead of a .orf?
A real ORF is written by Olympus cameras and holds the sensor's own readings (12 bits per channel, stored as losslessly compressed sensor data, with a preview and thumbnail) along with EXIF and Olympus maker notes, which also contain the preview. This converter reads the JPEG preview inside the NEF, not its sensor data, so it cannot make one either. The Linear DNG you get instead is Adobe's open raw format, and every editor that opens ORF files opens it with the same raw controls. It holds decoded pixels, so it adds no quality or dynamic range.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.