What is the SRF file format?
The .srf file extension is used by RAW image files generated by Sony digital cameras. Introduced in January 2004 with the Sony Cyber-shot DSC-F828, .srf is Sony's earliest camera raw format. The file stores data in uncompressed, unprocessed form exactly as it was captured by the camera's CMOS image sensor, wrapped in a little-endian TIFF container.
Image editing features
RAW images can be seen as digital counterparts to photo negatives and can be edited after having been saved into a file. Users can modify image parameters and save the finished photo as, for example, a JPEG or PNG image. Elements of an .srf image which can be edited include:
- contrast,
- saturation,
- sharpness,
- exposure,
- color temperature,
- white balance.
High-quality image
.srf files store high-quality, high-fidelity images because all information captured by the sensor is saved directly as raw image data - at 14 bits per pixel, yielding richer tonal detail than 8-bit processed formats. An .srf file from the DSC-F828 also embeds a full-resolution JPEG preview for quick display. One notable quirk is that part of the embedded metadata (the Sony MakerNote) is obfuscated with a proprietary encryption scheme; decoding tools such as ExifTool and LibRaw handle this transparently.
.srf is effectively a one-camera format: Sony moved on quickly, releasing .sr2 in 2005 and then the current .arw (Alpha RAW) format from 2006 onward. New Sony cameras no longer produce .srf files, but the format remains supported by most major raw converters through LibRaw-based decoding.
Security & safety
RISK: LOWSRF is passive image data - sensor pixels plus metadata, no executable code - so opening one is safe. Practical (non-malware) cautions: it is an obsolete, proprietary one-camera format, so back up originals and consider archiving to open DNG for longevity; and EXIF/ MakerNote metadata (camera, timestamps) travels with the file - strip it before publishing if privacy matters. Avoid sketchy 'SRF viewer/converter' download sites that bundle adware; use RawTherapee, darktable or IrfanView from their official pages.
Format details
in a nutshell- Garmin vehicle image (custom vehicle icon) - Bitmap image shown as the position marker in some Garmin GPS units; unrelated to the Sony raw photo.
- Surfer Grid / Golden Software SRF - Older Golden Software Surfer surface/grid data file used in contour mapping.
- Server Response File (Steinberg / various) - Occasionally a text settings/response file written by assorted server tools.
Programs that open SRF files
Windows5 apps
darktable
Open-source Import the SRF into the lighttable, edit in the darkroom, then export a JPEG/TIFF. 
Adobe Photoshop Camera Raw
Paid Open via Camera Raw to develop the SRF. Industry standard but subscription-based. 
RawTherapee
Open-source Open the .srf to develop it non-destructively (exposure, white balance) and export JPG/TIFF/PNG.
Raw Image Extension (Microsoft Store)
Free Install to show Sony raw thumbnails/previews in File Explorer and the Photos app.
IrfanView (+ RAW plugin)
Free Fast free viewer; with its RAW/FORMATS plugin it displays SRF and batch-converts to JPG. 
macOS3 apps
Linux3 apps
GIMP (+ darktable/RawTherapee loader)
Open-source GIMP opens SRF via its darktable/RawTherapee raw loader, then edits as a normal image. Technical details
deep spec| Container format | Little-endian TIFF (binary) |
| Byte order | Little-endian (Intel byte order, "II" marker) |
| Magic bytes | 49 49 2A 00 - little-endian TIFF header at offset 0 |
| Bit depth | 14 bits per pixel (raw sensor values) |
| Demosaiced color depth | 42-bit (3 × 14-bit) RGB after raw development |
| Compression | Uncompressed - lossless sensor data |
| MIME type | image/x-sony-srf |
| Maximum resolution | 3264 × 2448 px (8 MP, DSC-F828) |
| Typical file size | 5 MB - 13 MB per frame |
| Embedded preview | Full-size JPEG preview embedded inside the TIFF IFD structure |
| Metadata standard | EXIF + Sony MakerNote IFD |
| Metadata obfuscation | Sony MakerNote partially encrypted with a file-derived key; pixel data is not encrypted |
| Camera compatibility | Sony Cyber-shot DSC-F828 exclusively |
| Successor formats | .sr2 (2005), then .arw Alpha RAW (2006 onward) |
| Decoding support | LibRaw / dcraw-derived tools; MakerNote decoding is reverse-engineered |
| Operating system support | Windows, macOS, Linux |
| Released | January 2004 (Sony Cyber-shot DSC-F828) |
| Latest version | SRF (single generation, DSC-F828); superseded by SR2 then ARW |
| Specification | github.com |
SRF conversions
Community Q&A
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