Olympus ORF: The Micro Four Thirds RAW Format
ORF (Olympus Raw Format) is the RAW file format used by Olympus cameras and their successor OM System cameras. From the venerable E-M1 series to the modern OM-1 Mark II, every Olympus/OM System body saves RAW files with the .orf extension. The format stores 12-bit or 14-bit sensor data from Micro Four Thirds sensors (typically 16-20 megapixels, with the OM-1 series at 20 MP using a stacked BSI sensor).
Converting ORF to JPG is necessary when sharing photos via email, publishing on the web, sending to clients who do not use RAW editing software, or uploading to social media platforms. The Micro Four Thirds sensor size means ORF files are slightly smaller than full-frame RAW files (typically 15-25 MB versus 25-50 MB), which makes batch conversion faster.
ORF Format Specifications
| Property | Details |
|---|---|
| Sensor format | Micro Four Thirds (17.3 x 13.0 mm) |
| Color depth | 12-bit (older) or 14-bit (OM-1, E-M1X) |
| Compression | Lossless or lossy (camera-dependent) |
| Typical resolution | 16-20 MP (some High Res Shot: 50-80 MP) |
| File size | 15-25 MB standard, 50-80 MB High Res |
| Image stabilization | IBIS metadata included |
| Color profiles | Natural, Vivid, Flat, Muted, Portrait, i-Enhance |
| Art Filters | Stored as metadata, not baked in |
Olympus cameras are known for their distinctive color science — particularly the way they render blues and greens. When converting ORF to JPG, using Olympus's own processing (via Olympus Workspace) preserves this color character most faithfully.
Method 1: Olympus Workspace (Official Tool)
Olympus Workspace is the free official RAW processor from OM System. It applies the same color science and processing algorithms as the camera body:
- Download and install Olympus Workspace from the OM System website
- Import your ORF files
- Apply any desired adjustments (white balance, exposure, Art Filters)
- Select Edit → Batch → JPEG Export
- Choose quality (Fine = 95, Normal = 85), sRGB color space, and output directory
- Process the batch
This produces JPGs that match the camera's internal JPEG engine, including Olympus's characteristic rendering of skin tones, skies, and foliage.
Method 2: Command-Line Conversion
Using dcraw/LibRaw
# Basic conversion with camera white balance
dcraw_emu -w -T -o 1 -q 3 input.orf
# Convert TIFF to JPG
convert input.tiff -quality 92 output.jpg
Using ImageMagick Directly
convert input.orf -auto-orient -set colorspace sRGB \
-auto-level -quality 92 output.jpg
Batch Convert All ORF Files
mkdir -p jpg
for file in *.orf *.ORF; do
[ -f "$file" ] || continue
dcraw_emu -w -T -o 1 -q 3 "$file"
tiff="${file%.*}.tiff"
convert "$tiff" -quality 92 "jpg/${file%.*}.jpg"
rm "$tiff"
done
For more batch processing techniques, see our batch processing guide.
Method 3: Online Conversion
Use the ORF to JPG converter online for quick conversions without installing any software. Upload your ORF file and download a processed JPG. For other RAW formats, check the Image Converter.
Handling High Res Shot ORF Files
The Olympus/OM System High Res Shot feature captures 8 exposures and composites them into a single high-resolution ORF file (50 MP from a 20 MP sensor, or 80 MP in tripod mode). These files are significantly larger (50-80 MB) and require software that understands the composite format.
Olympus Workspace handles High Res Shot files natively. Third-party tools like Lightroom and Capture One also support them. Basic dcraw/LibRaw may not correctly process the composite — they may only decode the first exposure. If you see unexpectedly low resolution output from a High Res Shot ORF, use Olympus Workspace or Lightroom instead.
Quality and Settings Tips
JPG quality: For 20 MP Micro Four Thirds files, quality 90-92 produces 5-8 MB JPGs with excellent detail. Quality 85 gives 3-5 MB files suitable for web sharing. Below 80, you may notice softness in fine detail areas.
Color rendering: Olympus's color science favors accurate but pleasing rendering. If your converted JPGs look too flat compared to the camera's LCD preview, the camera was likely using the "Vivid" or "i-Enhance" color profile. Apply similar processing during conversion:
# Boost saturation slightly to match Vivid profile
convert input.orf -auto-orient -set colorspace sRGB \
-auto-level -modulate 100,120,100 -quality 92 output.jpg
The -modulate 100,120,100 increases saturation by 20% while keeping brightness and hue unchanged.
Noise handling: Micro Four Thirds sensors have smaller photosites than full-frame, which means more visible noise at high ISO (3200+). When converting high-ISO ORF files, consider applying light noise reduction:
convert input.orf -auto-orient -set colorspace sRGB \
-auto-level -despeckle -quality 92 output.jpg
Art Filters: Olympus Art Filters (Pop Art, Soft Focus, Grainy Film, Pin Hole, Diorama, Cross Process, Gentle Sepia, Dramatic Tone, Key Line, Watercolor, Vintage, Partial Color, Bleach Bypass) are stored as metadata in ORF files. They are only applied when using Olympus Workspace or the camera's internal JPG engine. Third-party converters ignore Art Filter metadata and produce a neutral conversion.
For more on image quality preservation, read our guide on how to resize images without quality loss.
Common Issues and Troubleshooting
"Unsupported file format" with newer cameras
The OM-1 Mark II and other recent OM System cameras may use updated ORF variants that older software does not recognize. Update your RAW processing software to the latest version. LibRaw versions from 2024 onward support all current OM System cameras.
Output looks very different from camera screen
The camera LCD shows a fully processed JPG preview with the selected Picture Mode (Vivid, Natural, etc.) and any Art Filters applied. RAW conversion without these adjustments produces a neutral, lower-contrast image. This is expected — the RAW file gives you the flexibility to apply your own processing.
Incorrect white balance
If the colors look too warm or too cool, the camera's auto white balance setting may not have been ideal. When using dcraw, the -w flag applies the camera's recorded WB. For a neutral rendering, use -a (auto white balance calculated from the image) instead:
dcraw_emu -a -T -o 1 -q 3 input.orf
Purple fringing in high-contrast edges
Micro Four Thirds lenses can show chromatic aberration (purple fringing) at wide apertures. This is corrected by in-camera processing and by Olympus Workspace, but not by generic RAW converters. In Lightroom, enable lens profile corrections for your specific Olympus lens.
Conclusion
Converting Olympus ORF to JPG is straightforward with the right tools. Olympus Workspace provides the most faithful reproduction of the camera's color science and Art Filters. For batch processing and automation, LibRaw and ImageMagick handle ORF reliably. The relatively modest file sizes of Micro Four Thirds RAW files make batch conversion fast even on modest hardware.
Ready to convert? Try our free ORF to JPG converter — no registration required.



