Reference

ORF (Olympus RAW)

ORF (Olympus Raw Format) is the RAW image format used by Olympus and OM System cameras, holding unprocessed sensor data. Files are large (often 15–30 MB) and need the maker’s software, Lightroom/Adobe Camera Raw, or conversion to DNG or JPEG to edit and share.

Files & formatsGeneral

ORF (Olympus RAW)

Also known as: Olympus RAW, OM System RAW, ORF file, how to open ORF

Olympus / OM System RAW format
Micro Four Thirds RAW, often 15–30 MB
Opens in OM Workspace, Lightroom, or Camera Raw

What an ORF file is

ORF is the proprietary RAW format Olympus — now OM System — cameras write when shooting RAW. It stores the raw sensor readings, an embedded JPEG preview, and EXIF metadata, so exposure and color stay editable after the shot.

ORF files come from Micro Four Thirds sensors, so they are often a little smaller than full-frame RAW files, but they are still far heavier than JPEG and add up quickly across a shoot.

How to open and convert ORF

ORF opens in OM Workspace (the maker’s software), Adobe Lightroom and Camera Raw, Apple Photos/Preview on recent macOS, and most full editors. Generic viewers often cannot display it.

Export to JPEG for sharing, or convert ORF to DNG to keep RAW flexibility in a widely supported container. Remove the original RAW only once you no longer need to re-edit it.

Related terms

Keep reading the reference.

Files & formatsCamera RAW (CR2, NEF, ARW)Camera RAW is the umbrella for manufacturer-specific files that store unprocessed data straight off the camera sensor — Canon CR2/CR3, Nikon NEF, Sony ARW, and others. They keep maximum editing flexibility, which makes them far larger than the JPEG or HEIC the same shot would produce.General Files & formatsDNG (digital negative)DNG (Digital Negative) is an open raw image format created by Adobe. Like other raw files, it stores the unprocessed sensor data from a camera for maximum editing flexibility — and like all raw files, it takes far more storage than a JPEG or HEIC.GeneraliOS Files & formatsRAW imageA RAW image is the unprocessed data straight from a camera sensor, before any in-camera compression or color processing. It preserves maximum editing flexibility but produces very large files — many times bigger than a JPEG or HEIC of the same shot.GeneraliOS Files & formatsJPEGJPEG (.jpg) is the most widely supported photo format. It uses lossy compression to shrink photographs dramatically, trading a small amount of detail for much smaller files. It has no transparency and is larger than newer formats like HEIC or WebP at the same quality.General

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