About ORF Files
Olympus RAW ORF
ORF is Olympus camera RAW format.
Family
Raster & Vector Images
Extension
.orf
MIME Type
image/x-olympus-orf
Can Use As
HOW ORF
CAME TO BE.
ORF — Olympus Raw Format — shipped with the Olympus E-1 in 2003, the first 4/3 Four Thirds system camera. Olympus pioneered the Micro Four Thirds mirrorless standard with Panasonic in 2008, and ORF remained the raw format across both mounts. In 2020 Olympus sold its imaging business to Japan Industrial Partners, who relaunched under the OM SYSTEM brand; ORF continues unchanged.
ORF is a TIFF variant with Olympus makernotes — nothing architecturally exotic. What made Olympus distinctive was computational in-body features baked into the format: Live Composite long exposure, Pro Capture pre-burst buffering, Hand-Held High Res (16-shot pixel shift), and Live ND simulation. Many of those show up as metadata flags or multi-frame containers inside the ORF.
CURIOSITIES &
TRIVIA.
Olympus's "Live Composite" mode stores a long-exposure stack as a single ORF — typically 30+ minutes of astrophotography in one file.
The OM-1's "Hand-Held High Res" feature creates 50 MP or 80 MP composite ORFs from 16 rapid captures — no tripod needed.
When Olympus exited the camera business in 2020, the ORF format transferred intact to OM Digital Solutions (OM SYSTEM).
ORF files from Four Thirds cameras (2003-2008) use a 4/3 aspect ratio sensor — the crop factor is 2× vs full-frame.
Olympus's flagship bodies shoot at 14-bit ORF but store data in a compact 12-bit lossy variant by default to save card space.
STRENGTHS &
LIMITATIONS.
Strengths
- Compact files relative to sensor size (Four Thirds is smaller than APS-C).
- Computational photography features (Live Composite, Pro Capture) baked into format.
- Stable across 20+ years of Olympus/OM SYSTEM bodies.
- In-body stabilization means ORF handheld shots rival tripod work.
Limitations
- Smaller sensor means less dynamic range than full-frame raws.
- Lossy compressed ORF is the default — hidden quality loss.
- Market share is small; fewer tutorials and fewer Lightroom profiles.
- Proprietary with no official spec.
Typical Sizes & Weights
20 MP ORF (OM-1, E-M1 III)
18-25 MB
50 MP Hand-Held High Res composite
60-80 MB
80 MP Tripod High Res ORF
100-140 MB
Technical Specifications
- MIME type
- image/x-olympus-orf
- Extension
- .orf
- Container
- TIFF/EP with Olympus MakerNote
- Sensor format
- Four Thirds / Micro Four Thirds
- Bit depth
- 12 or 14-bit
CONVERT FROM
ORF
Common Use Cases
Olympus photography
Related Formats
Popular comparisons
ORF vs PNG
Differences, file size, and when to choose each format.
ORF vs WEBP
Differences, file size, and when to choose each format.
ORF vs AVIF
Differences, file size, and when to choose each format.
ORF vs GIF
Differences, file size, and when to choose each format.
ORF vs BMP
Differences, file size, and when to choose each format.
ORF vs TIFF
Differences, file size, and when to choose each format.
Popular ORF conversions
The most-requested destinations when starting from ORF.
Frequently Asked Questions about ORF
Frequently Asked Questions
ORF (Olympus RAW ORF) is an image format used to store raster graphics — a two-dimensional grid of pixels describing a picture. It is part of the raster & vector images family and designed around a specific trade-off between file size, visual fidelity, and feature support (transparency, colour depth, compression type). Photographers, web designers, and content creators choose ORF when its particular strengths match the publishing target.
Most desktop photo viewers (Windows Photos, macOS Preview, GIMP, Photoshop, Affinity Photo) open ORF natively. On mobile, iOS Photos and Google Photos display ORF in the gallery when supported by the OS. If the format is rare or new, convert to JPG or PNG first — both are universally readable — using our ORF to JPG or ORF to PNG converter.
Upload the ORF to KaijuConverter and pick a target format (JPG, PNG, WebP, HEIC, TIFF, BMP, SVG, PDF). The conversion runs in the browser via ImageMagick and returns a download in seconds. No account or installation required; both input and output delete automatically within two hours.
It depends on the task. JPG is the smallest file size for photographs; PNG is lossless with transparency; ORF has its own niche that may favour colour depth, animation, or encoding efficiency over one or both of those. For the final web publish, test all three and measure file size plus visible quality on real content.