ORF Format Guide

Available Conversions

About ORF Format

ORF (Olympus Raw Format) is Olympus's proprietary RAW image format used across their digital camera lineup, including the E-series DSLRs, OM-D mirrorless cameras, and PEN series cameras. As a RAW format, ORF files contain minimally processed data directly from the camera's image sensor, preserving all the information captured at the moment of exposure without the quality loss associated with in-camera JPEG processing. Unlike compressed formats that discard image data, ORF files store the complete sensor data along with metadata about camera settings, lens information, white balance, Picture Mode settings, Art Filters, and shooting conditions. This gives photographers maximum flexibility for post-processing adjustments to exposure, white balance, color grading, contrast, sharpening, and noise reduction without quality degradation. ORF files are based on the TIFF specification with Olympus-specific extensions and use lossless compression, resulting in file sizes typically ranging from 10 to 25 MB per image depending on the camera's resolution and the Micro Four Thirds sensor size. Olympus cameras are particularly known for their advanced computational photography features, and ORF files preserve data from features like Live Composite, High Resolution Shot mode, focus stacking, and the various Art Filters, allowing photographers to reprocess these effects in post-production.

History of ORF

Olympus introduced the ORF format with their early digital cameras in the late 1990s, establishing it as their proprietary RAW file standard. The format gained professional credibility with the launch of the Olympus E-1 in 2003, the company's first professional-grade digital SLR featuring a Four Thirds sensor and weather-sealed construction aimed at photojournalists and professional photographers. The E-series evolved through cameras like the E-300 (2004), which brought Four Thirds technology to enthusiasts, the E-3 (2007) with improved autofocus and image stabilization, and the E-5 (2010), which represented the pinnacle of Olympus's Four Thirds DSLR development. In 2008, Olympus and Panasonic jointly introduced the Micro Four Thirds (MFT) standard, which eliminated the mirror box and optical viewfinder to create much more compact camera bodies while maintaining the same sensor size and lens mount. This led to two groundbreaking camera lines: the PEN series, beginning with the E-P1 in 2009, which revived Olympus's classic PEN design in a compact mirrorless form; and the OM-D series, launched with the OM-D E-M5 in 2012, which combined professional-grade features with compact bodies and introduced industry-leading 5-axis in-body image stabilization. The OM-D E-M1 (2013) and its successors (Mark II in 2016, Mark III in 2020) became Olympus's flagship cameras, featuring advanced autofocus, weather sealing, high-speed shooting, and innovative features like Live Composite (for long exposure compositing), High Resolution Shot mode (combining multiple exposures for 50-80MP output), and advanced focus bracketing for focus stacking. Throughout this evolution, the ORF format advanced to support higher resolutions, more sophisticated Art Filters (12 filters with multiple variations), advanced white balance options, and the computational photography features that distinguished Olympus cameras. The format gained strong support from RAW processing software including Adobe Lightroom and Photoshop, Capture One, DxO PhotoLab, and Olympus's own Workspace software (successor to Olympus Viewer). In 2021, Olympus's camera division was acquired by Japan Industrial Partners and rebranded as OM System (OM Digital Solutions), continuing the OM-D line with cameras like the OM-1 (2022), which maintains ORF format compatibility while introducing new computational photography features and improved autofocus powered by AI.

Key Features and Uses

ORF files store unprocessed, linear sensor data in 12-bit depth (standard across Olympus Micro Four Thirds cameras), preserving significantly more tonal information than 8-bit JPEG files—12-bit ORF files capture 4,096 tonal levels per color channel compared to JPEG's 256 levels. While Micro Four Thirds sensors are physically smaller than full-frame sensors, modern Olympus sensors capture impressive dynamic range of 12-13 stops, providing substantial latitude for recovering shadow and highlight detail in post-processing. ORF files include comprehensive EXIF metadata containing all camera settings: shutter speed, aperture, ISO sensitivity, focal length, lens identification, autofocus point selection, metering mode, Picture Mode settings, Art Filter applied (if any), and in-body stabilization data. The format stores the Bayer array color filter data from the sensor, allowing photographers to adjust white balance after capture without penalty, unlike JPEG where white balance is permanently baked in during processing. ORF files preserve special shooting mode data: Live Composite exposures store individual frame data allowing reprocessing; High Resolution Shot mode files contain the combined 50-80 megapixel output from the sensor shift technology; focus bracketing sequences include metadata for subsequent focus stacking. Olympus's renowned TruePic image processors embed advanced computational photography data that can be adjusted in RAW processing: Art Filters can be modified or removed entirely, Picture Modes adjusted, and lens corrections refined. The format includes Olympus-specific lens correction data, allowing automatic correction for distortion, vignetting, lateral chromatic aberration, and diffraction specific to each M.Zuiko lens. ORF files from Olympus's professional lenses preserve metadata about dust reduction, image stabilization performance, and even the specific lens serial number for quality control purposes.

Common Applications

ORF files are essential for photographers using Olympus and OM System cameras across numerous photographic disciplines. Landscape photographers are particularly drawn to the Olympus system for its combination of weather-sealed bodies, compact size for hiking and travel, and features like Live Composite (perfect for star trails and light painting) and High Resolution Shot mode (producing 50-80MP images from tripod), all of which are preserved in ORF files for maximum post-processing flexibility. Travel photographers rely on ORF format to capture the full quality potential of the compact Micro Four Thirds system, which offers professional image quality in camera bodies and lenses that are 30-40% smaller and lighter than equivalent full-frame systems. Macro photographers shoot ORF files to leverage Olympus's renowned macro capabilities including the M.Zuiko 60mm f/2.8 Macro and 90mm f/3.5 Macro IS PRO lenses, using focus stacking features that create ORF files containing precise focus point metadata for combining multiple exposures into images with extraordinary depth of field. Wildlife photographers using cameras like the OM-D E-M1X or OM-1 capture ORF files at high frame rates (up to 50-120 fps with electronic shutter) while benefiting from the smaller sensor's inherent "crop factor" that makes telephoto lenses more effective (a 300mm lens provides 600mm equivalent field of view). Street and documentary photographers value the discrete size of OM-D and PEN cameras, shooting ORF files that preserve Olympus's excellent color science and shadow recovery capabilities while remaining inconspicuous. Astrophotographers extensively use ORF files from Live Composite mode, which intelligently combines multiple long exposures to create star trails and Milky Way images without the stacking artifacts of traditional methods. Underwater photographers shoot ORF files with Olympus's extensive lineup of underwater housings and lenses, taking advantage of the smaller system size for more portable underwater setups and the RAW files' ability to correct the color shifts inherent in underwater photography. Architecture and real estate photographers use ORF files with Olympus's wide-angle lenses and the High Resolution Shot feature for detailed interior and exterior captures. Event photographers benefit from Olympus's industry-leading 5-axis in-body image stabilization (up to 7.5 stops of compensation), shooting ORF files that capture sharp images in low light without high ISOs. Fine art photographers embrace Olympus's Art Filters, shooting ORF files that preserve the original RAW data beneath the applied filter, allowing complete reprocessing flexibility while exploring creative effects.

Advantages and Disadvantages