ERF to AVIF Converter

ERF or AVIF — Which Copy of the Photo Should You Keep?

If you have Epson R-D1 files sitting on a drive, you are really choosing between two different jobs. ERF is a negative: uncompressed 12-bit sensor data that can still be re-developed years later, but that almost nothing opens. AVIF is a delivery format: an AV1-coded still that current browsers display natively and that is far smaller than a JPEG of comparable quality. The short answer is that you want both — archive the .erf, publish the AVIF — and this page converts one into the other.

Side-by-side: ERF vs AVIF

When to Stay on ERF

• You might still re-develop the shot. The 12-bit readout is what lets you recover blown highlights, reset white balance and lift shadows. Once it is rendered, that is gone for good.
• It is your only copy of an irreplaceable frame. The R-D1 line was discontinued and no camera makes new ERFs, so treat the originals as negatives.
• Your raw workflow already reads them. LibRaw's supported-camera list covers the R-D1, R-D1s and R-D1x, so the tools built on it open your files today.
• You need the embedded shooting metadata intact. ExifTool reads and writes EXIF, IPTC, XMP and ICC data in ERF, including the Epson-specific white-balance tag that raw decoders use to set WB coefficients.

When to Convert to AVIF

• The picture has to appear on a web page. No browser displays an ERF; almost every current one displays an AVIF without a plug-in or polyfill.
• Storage or bandwidth is the constraint. An ERF stores its pixels uncompressed — 6.1 million photosites at 12 bits each is roughly 9 MB of pixel data by simple arithmetic, before metadata and the embedded preview. AVIF applies AV1's intra-frame coding to a rendered version of the same picture.
• You want headroom that JPEG cannot give. AVIF carries 10- and 12-bit images, HDR and wide colour gamut; JPEG stops at 8-bit SDR.
• You want one file that also works as a thumbnail source. AVIF supports progressive rendering through multi-layer images, so a large photo can start appearing before it has finished downloading.

AVIF vs the Other Outputs for a Rendered R-D1 Frame

How to Convert ERF to AVIF

1. Upload Your ERF Files: Drag and drop your .erf files onto the page or click "+ Add Files". Several R-D1, R-D1s or R-D1x frames can be queued and converted with one set of settings.
2. Pick a Quality Preset: Under "Image Compression", "Quality Preset" is preselected to "Very High (Recommended)". Step down through High, Medium, Low and the rest to shrink the file, or choose "Highest" for the most conservative encode.
3. Or Target a Specific file size, and set Image resolution (Optional): Switch the compression mode to "Specific file size" and name a size in KB or MB to let the encoder aim for it. "Image resolution" stays on "Keep original" unless you pick a Preset Resolution, a percentage, or an explicit Width x Height.
4. Convert and Download: Click "Convert" and save the AVIF. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

Frequently Asked Questions

Is AVIF actually better than JPG for a 6-megapixel R-D1 frame?

For anything shown on a screen, yes. AVIF applies AV1's intra-frame coding tools to the still image, which is a far more capable toolset than JPEG's DCT, so at a given visual quality the AVIF is smaller. It also carries 10- and 12-bit images, HDR and wide gamut, none of which 8-bit JPEG can do. The trade is reach: JPEG opens in literally everything, whereas AVIF needs Chrome 85+, Firefox 93+, Safari 16.4+ or Edge 121+. If the file is going into a web upload form or an old photo app, choose ERF to JPG instead.

Will I lose the raw editing latitude?

Yes, and that is inherent rather than a limitation of this converter. An ERF holds undemosaiced 12-bit sensor readings, so white balance, exposure and tone are still adjustable parameters. Producing any viewable image — AVIF, JPEG, PNG or TIFF — requires demosaicing that data and committing to one interpretation. Keep the original .erf as your master and treat the AVIF as a copy you can always regenerate.

Is ERF an uncompressed raw format?

Yes, despite what several converter sites say. darktable's RawSpeed decodes ERF using its uncompressed decompressor, reading 12-bit samples MSB-first with a control byte inserted roughly every ten pixels. There is no Huffman stage and no lossy compression on the sensor data — which is exactly why the files are large for a 6-megapixel camera, and why converting to AVIF shrinks them so dramatically.

Why can't I set Image Quality (%) or Target file size (%) on this page?

Because they are deliberately not part of the conversion flow. We checked the option surface for this page: on image conversion pages the compression group renders "Quality Preset" and "Specific file size" only, while the percentage-based quality and target-size sliders are reserved for the compression tools. Quality Preset is the control to reach for first; use "Specific file size" when you have a hard byte budget to hit.

Should I archive my R-D1 photos as AVIF?

No. AVIF is a delivery format — it bakes in one render and discards the raw latitude, so it cannot serve as a negative. For preservation, keep the original .erf files; if you also want a non-raw archival master that a document or print workflow can read, ERF to TIFF is the better companion. AVIF is what you publish, not what you keep.

Does the AVIF keep the transparency and the shooting metadata?

There is no transparency to keep — an R-D1 photograph is fully opaque, and AVIF's alpha support (via AV1 alpha image items) simply goes unused. Metadata is a different story: an ERF carries EXIF, IPTC, XMP and ICC data plus Epson's own white-balance tag, and a rendered delivery file is not a reliable place to look for all of it. If the shooting data matters to you, keep the original file, which is the only copy guaranteed to hold everything.

What is AVIF built on, and who maintains it?

AVIF is the AV1 Image File Format, maintained by the Alliance for Open Media; the current specification is version 1.2.0, finalised on 16 October 2025. It stores a subset of an AV1 bitstream inside a HEIF file, which in turn sits on the ISO Base Media File Format — so an AVIF is structurally a close cousin of HEIC, with AV1 in place of HEVC and no patent-licensing questions attached.

What happens to my uploaded ERF files after conversion?

They are uploaded over an encrypted connection, rendered and re-encoded to AVIF on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public. Because ERF stores its sensor data uncompressed, upload time is usually the longest part of the job rather than the encode. For every other output available from the same source, see the ERF converter hub.