What is an ORF file?
ORF stands for Olympus Raw Format. It was created by Olympus and first released in the early 2000s. ORF is the raw format of Olympus cameras, kept by OM System after it took over the brand. Its header starts with IIRO rather than the usual TIFF signature, one reason some older programs refuse it.
| Type | image |
|---|---|
| Compression | Lossless |
| Colour | raw sensor data, usually 12 or 14 bits per pixel |
| Transparency | No |
| Animation | No |
| In a browser | does not open in browsers; macOS Photos and Preview, Lightroom and OM Workspace open it |
| Common uses | Olympus E, PEN and OM-D cameras and OM System models |
| MIME type | image/x-olympus-orf |
Which format should you convert ORF to?
- ORF to JPG for photos that must open everywhere and stay small.
ORF is lossless, so converting it to a lossy format is where the file gets much smaller.
How to open an ORF file
An ORF file does not open in a web browser, but most photo apps read it. Here is what works on each device.
| Windows | The Photos app opens it with Microsoft's free Raw Image Extension; OM Workspace (free), Lightroom and darktable edit it. |
|---|---|
| Mac | Photos and Preview open it; OM Workspace (free), Lightroom and darktable edit it. |
| iPhone and iPad | The Files app previews it and Photos opens it once imported; Lightroom Mobile edits it. |
| Android | Few Android apps read ORF. Convert it to JPG here to view it anywhere. |
Want the technical details? See what a .orf file is, with its MIME type, file signature and a viewer.
ORF compared with other image formats
How ORF stacks up against the formats people most often convert it to or from:
| Format | Compression | Transparency | Released | Best for |
|---|---|---|---|---|
| ORF | Lossless | No | the early 2000s | Olympus E, PEN and OM-D cameras and OM System models |
| JPG | Lossy | No | 1992 | camera photos, web images and email attachments |
| PNG | Lossless | Yes | 1996 | screenshots, logos, diagrams and anything with transparency |
| WebP | Either | Yes | 2010 | images served by websites to save bandwidth |
| HEIC | Lossy | Yes | 2017 | photos taken on iPhones and iPads since iOS 11 |
How to use the ORF converter
- Choose the format you want in the Convert to menu.
- Drop your ORF files on the box, or press Choose ORF files. Several files can go in at once.
- Adjust the settings if you need to; the defaults suit most people.
- Press Convert and save each file with its Download button. The file is converted on our server and deleted as soon as the result is sent back.
Tips for converting ORF files without losing quality
ORF is lossless, so it is a good source for any conversion. Converting it to a lossy format is where the file gets much smaller, and converting it to another lossless format keeps every pixel.
- Keep the raw file. It holds the full sensor data, with far more room for adjusting exposure and colour than any JPG or PNG made from it.
- Choose JPG to share or upload a photo, and PNG or TIFF when the picture will be edited further, since they add no compression loss.
- The conversion is a neutral development with the white balance the camera recorded. For an edited look, develop the file in Lightroom, darktable or RawTherapee instead.
- The server accepts files up to 25 MB, which fits the raw files of most cameras; very high-resolution cameras can go past it.
Convert ORF files from the command line
LibRaw and ImageMagick do the same on your own computer:
dcraw_emu -w -o 1 -q 3 -T input.orf
magick input.orf.tiff -quality 92 output.jpgConverting on your own computer keeps the file entirely local, which is worth it for very large or very sensitive documents. For everything else, the converter on this page does it without installing anything.
ORF converter FAQ
What is an ORF file?
ORF stands for Olympus Raw Format, an image format created by Olympus in the early 2000s. ORF is the raw format of Olympus cameras, kept by OM System after it took over the brand. Its header starts with IIRO rather than the usual TIFF signature, one reason some older programs refuse it.
How do I open an ORF file?
ORF does not open in browsers; macOS Photos and Preview, Lightroom and OM Workspace open it. If the program you need will not open it, convert it to a more widely supported format above.
What is the most common ORF conversion?
ORF to JPG is the conversion people search for most. The ORF is developed by LibRaw, the open-source camera RAW decoder, on our conversion server: the sensor data is turned into a full-colour picture with the white balance the camera recorded, AHD demosaicing and standard sRGB colour.
Does converting ORF files here upload them?
Yes. ORF conversions need LibRaw and ImageMagick, open-source programs that cannot run in a browser, so they run on our conversion server. The file is uploaded, converted, and deleted together with the result as soon as the result has been sent back to you. Nothing is kept.
Is the ORF converter free?
Yes. There is no sign-up and no watermark. Conversions that use our server accept files up to 25 MB, with a fair-use limit per hour. The site is supported by advertising.
Can I convert ORF files on iPhone or Android?
Yes. Open this page in Safari on iPhone and iPad, or in Chrome on Android, choose your ORF files and download the results to your Downloads folder.
Can I convert several ORF files at once?
Yes. Drop as many as you like; they are converted one after another, each with its own download button.