X3F to AV1 Converter

How to Convert X3F to AV1 Online

1. Upload Your X3F Files: Drag and drop or click "+ Add Files" to load Sigma Foveon RAW files (.x3f) from a Sigma SD, DP, dp Quattro, fp, or fp L camera. Batch is supported — drop an entire shoot at once. Files stay in your browser session; nothing is sent to a server account.
2. Pick a Merge Strategy and Duration: Switch Merge strategy between Merge images (one continuous AV1 slideshow with all frames concatenated) and Video per image (one AV1 file per X3F). Set Image Duration from 1/60 second up to 10 seconds per frame — 5 seconds per frame is the default, 1/24 second mimics film at 24 fps.
3. Tune Quality and Resolution (Optional): Pick a Quality Preset of Very High (Recommended), High, Medium, Low, or Lowest in Constant Quality (CRF-style — fixed perceptual quality, variable size) or Constraint Quality (caps the upper bitrate) mode. Set Video resolution to Keep original, choose a Fixed Resolution (4320p / 2160p / 1440p / 1080p / 720p / 480p / 360p / 240p), pick a Preset Resolution (1920×1080, 3840×2160, vertical 1080×1920, etc.), or enter custom width/height. Change Background Color from the default Black if your X3Fs don't fill the target aspect ratio.
4. Convert and Download: Click "Convert" and grab each AV1 file individually or as a ZIP. No sign-up, no watermark, no email gating.

Why Convert X3F to AV1?

X3F is Sigma's proprietary RAW format for Foveon X3 sensors — the three-layer photodiode stack first shipped on the Sigma SD9 in 2002 and used since across SD, DP, dp Quattro, and fp/fp L bodies. Foveon files are large, only natively readable in Sigma Photo Pro and a handful of RAW processors, and impossible to share or stream as photos. Re-rendering a folder of X3F frames as a single AV1 video gives you a portable, browser-playable, royalty-free deliverable that's typically 30% smaller than HEVC for the same visual quality (per the Alliance for Open Media's compression benchmarks). Typical scenarios:

• Time-lapse and astrophotography — Sigma SD Quattro and fp L Foveon sensors are popular for low-noise long exposures; a 600-frame star trail at 1/24 second per frame becomes a 25-second AV1 clip at ~30 fps that streams on YouTube and Vimeo without re-uploading the RAW masters.
• Shoot review slideshows for clients — A wedding or product shoot dumps directly into one AV1 file at 5 seconds per frame, ready to drop into an email or Slack channel. AV1 plays inline on Chrome, Firefox, and Edge with no plug-in.
• Stock and portfolio reels — AV1 is the default 4K codec on YouTube for capable devices, so a 3840×2160 reel uploaded as AV1 avoids YouTube's re-encode generation loss.
• Archive and proof Foveon RAWs in a portable container — Most people don't have Sigma Photo Pro installed. A single AV1 file in an MP4/MKV/WebM container plays in VLC, mpv, modern browsers, and Apple devices running on M3 or later silicon.
• Replace HEVC slideshows to dodge licensing — Unlike H.265, AV1 is royalty-free under the Alliance for Open Media patent license — useful for open-source projects, public-broadcast workflows, and apps that ship to platforms where HEVC patent fees are a concern.
• Cut bandwidth for large galleries — Netflix reported about 30% of streams used AV1 as of December 2025; the bitrate savings vs. H.264 land around 50% at the same quality, which directly reduces CDN bills for self-hosted galleries.

Need a different output? Render the same X3Fs as MP4 or WebM instead, or export individual frames as JPG or PNG for stills work. Once your AV1 is built, Compress AV1 can shrink it further for email or chat.

AV1 vs HEVC vs H.264 — Pick the Right Codec for a Slideshow

Quality Preset Cheat Sheet (Constant Quality mode)

The Constant Quality mode maps to an AV1 CRF (Constant Rate Factor) value internally. Lower CRF = higher quality and larger file. Treat these as starting points for a 1080p slideshow at ~30 fps:

CRF mappings vary by encoder build (libaom vs SVT-AV1); the values above are typical libaom-style ranges. AV1 CRF generally runs higher than x264 CRF for the same perceptual quality.

Frequently Asked Questions

Why convert a RAW image format like X3F into a video codec like AV1?

Because AV1 is the only practical way to package a sequence of Foveon X3F frames into a single file that streams in a browser, posts to YouTube without re-encoding, and stays small. X3F itself is a still-image RAW container; turning a folder of them into AV1 produces a slideshow or time-lapse that anyone can watch. The conversion demosaics each Foveon frame, scales it to your target resolution, and encodes the sequence with AV1 — you lose the editable RAW data but gain a portable deliverable.

Will I lose Foveon's three-layer color depth?

Yes — any video codec, AV1 included, encodes to YUV 4:2:0 8-bit (or 10-bit if you target it specifically) and discards the per-pixel three-layer color samples that make Foveon distinctive. If you need to preserve the original RAW for re-editing, keep the X3F files and only treat the AV1 export as a deliverable. For stills that retain more of the Foveon character, export individual frames as PNG or TIFF instead.

How is AV1 different from H.265 (HEVC) for this use case?

Three things matter. First, licensing — AV1 is royalty-free under the Alliance for Open Media patent license; HEVC has three active patent pools (MPEG LA, HEVC Advance, Velos Media) that charge encoder/decoder fees and per-stream content royalties. Second, compression — AV1 is roughly 15–30% smaller than HEVC at matching quality per AOMedia's published comparisons. Third, browser playback — AV1 plays natively in Chrome 70+, Firefox 67+, and Edge 121+, while HEVC needs a paid Microsoft extension on Edge and partial Firefox support that only landed in Firefox 134.

Which Sigma cameras produce X3F files?

Every Sigma camera with a Foveon X3 sensor, starting with the SD9 in 2002. That spans the SD-series DSLRs (SD9, SD10, SD14, SD15, SD1, SD1 Merrill), the DP-series compacts (DP1/DP2/DP3 and their Merrill variants), the dp Quattro series (dp0/dp1/dp2/dp3 Quattro), the SD Quattro mirrorless bodies, and the Bayer-sensor fp/fp L (which also write X3F when configured for Sigma Photo Pro workflows). Files from older bodies use the original Foveon X3 layout; Quattro bodies use a modified Quattro X3 layout — both are read.

What frame rate does my AV1 output get?

The encoder sets the output frame rate from your Image Duration: 1 second per frame yields ~1 fps, 5 seconds per frame yields 0.2 fps (you'll usually want playback software to handle stills), and 1/24 second per frame yields a film-rate 24 fps clip suitable for time-lapses. For a smooth slideshow at standard playback rates, use 1/24, 1/30, or 1/60 second per frame; for a paced slideshow with each photo on screen, use 2–10 seconds per frame.

Will the AV1 file play on iPhone, Mac, or Apple TV?

Conditionally. AV1 hardware decoding shipped on Apple Silicon M3 (Macs from late 2023+), iPhone 15 Pro and 15 Pro Max (A17 Pro chip), iPhone 16 series, and Apple TV 4K (3rd generation, 2022 onward with the A15 Bionic). Older Apple devices fall back to software decoding in Safari 17+, which works for 1080p but can struggle at 4K. If you need universal Apple compatibility today, render the same shoot as MP4 with H.264 instead.

How big will the output file be?

Roughly: for a 1080p AV1 slideshow at the Very High preset, expect about 1–3 MB per minute of playback for talking-head-style stills, 3–8 MB per minute for high-detail nature/landscape stills, and 10–30 MB per minute for 4K time-lapses with lots of motion. AV1 sizes can vary 2–3× depending on scene complexity since CRF allocates bits where they're needed. If you need a hard target, use Constraint Quality mode to cap the maximum bitrate.

Why is converting X3F slower than converting a JPEG or PNG to AV1?

Two reasons. First, X3F is a Foveon RAW format — the converter has to demosaic the three-layer sensor data and apply white-balance and color-profile decoding before it has pixels to encode, which is heavier than reading a JPEG. Second, AV1 encoding itself is slow — libaom is roughly 5–20× slower than x264 at comparable quality, in exchange for the size savings. A 100-frame X3F → AV1 1080p conversion can take several minutes; 4K can take 10× longer. SVT-AV1-backed encoders are faster but still trail H.264.

Can I add an audio track to the AV1 slideshow?

Not from this page — the X3F-to-AV1 flow is image-to-video with no audio input. To add a soundtrack, convert to AV1 here first, then combine the AV1 with an audio file using a video editor (DaVinci Resolve, Shotcut, and Kdenlive all import AV1) or remux with ffmpeg (ffmpeg -i slideshow.mp4 -i music.mp3 -c copy out.mp4).