ERF File Format (.erf)
An ERF file holds the raw color filter array data from an Epson R-D1 or R-D1s digital rangefinder, wrapped in the TIFF/EP structure alongside an embedded thumbnail and Exif metadata.
ERF at a glance#
| Full name | Epson RAW Format |
|---|---|
| File extension | .erf |
| Category | Image Files |
| Developer | Epson |
| First released | 2004 |
| MIME types | image/x-epson-erf |
| Compression | Lossless |
| FileFlip support | FileFlip reads this format but does not write it |
What a .erf file can hold#
These are the things a ERF file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Embedded metadata | Yes |
|---|
Strengths and limitations of ERF#
What ERF does well
- Built on the TIFF/EP structure rather than a fully proprietary container, so any TIFF-aware parser can read its IFDs
- Still decoded by ExifTool and libopenraw-based tools long after Epson stopped making camera bodies
Where ERF falls short
- Written by only two camera models, the R-D1 and its minor revision the R-D1s, both discontinued
- Epson left the camera body business in 2014, so no new hardware will ever produce another ERF file
Keep a file as ERF only if it is an original R-D1 or R-D1s capture you are archiving unchanged.
Convert ERF to DNG or TIFF for long-term storage or editing in current software, since the only two cameras that ever wrote the format stopped being made years ago.
How to open a .erf file#
A .erf file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts ERF into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | RawTherapee, darktable, digiKam, ExifTool |
| macOS | RawTherapee, darktable, digiKam, ExifTool |
| Linux | RawTherapee, darktable, digiKam, ExifTool |
| Web | FileFlip |
ERF questions people ask#
What camera shot this ERF file?
ERF files come from only two cameras, the Epson R-D1 rangefinder released in 2004 and its 2006 update the R-D1s. Epson built the R-D1 with Cosina, pairing a Leica M-mount rangefinder body with Epson's own sensor electronics and image processing.
Can I still open an ERF file?
Yes. ERF files open in RawTherapee, darktable and digiKam through the libopenraw decoding library, and ExifTool reads their embedded Exif metadata. Epson never updated its own raw software after leaving the camera market, so a current raw processor is the practical option.
What should I convert ERF files to?
Converting ERF to DNG or TIFF is worth doing for long-term storage, since Epson exited the camera body business in 2014 and no software vendor has a reason to add new support for a format tied to two discontinued cameras.
Converting ERF files#
Convert ERF to another format
- ERF to AsciiDoc
- ERF to AVIF
- ERF to BBCode
- ERF to BibTeX
- ERF to BMP
- ERF to BMP2
- ERF to BMP3
- ERF to CBZ
- ERF to Djot
- ERF to DocBook
- ERF to DOCX
- ERF to DokuWiki
- ERF to EPUB
- ERF to FB2
- ERF to GIF
- ERF to GIF87
- ERF to Haddock
- ERF to HDR
- ERF to HTML
- ERF to ICML
- ERF to ICO
- ERF to ICON
- ERF to IPYNB
- ERF to Jira
See every ERF conversion (38 more)
FileFlip does not write .erf files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.