Convert X3F to APNG Online

Make an Animated APNG from Sigma X3F Photos

Turn a sequence of Sigma X3F RAW frames into one looping animated PNG: upload your Foveon shots in order, set a frame rate, and download a single APNG. This is a maker, not a one-to-one converter — each X3F you add becomes a frame, so a bracketed set, a focus-stack run, or a timelapse from a Sigma SD or DP body plays back as one animation. Because APNG keeps full 24-bit color losslessly, the demosaiced Foveon tones stay smooth and banding-free instead of being crushed to GIF's 256-color palette. Upload a single X3F and you get a clean one-frame APNG.

How to Convert X3F to APNG

1. Upload Your X3F Files: Drag and drop or click "Add Files" to add your Sigma RAW frames straight from an SD card or folder. They become frames in the order you add them, so arrange the sequence before converting (only .x3f files are accepted here).
2. Set the Frame Rate: Pick a value from the Framerate dropdown — 10 FPS (Recommended) for a normal loop, or slower (1-5 FPS) for a slideshow feel and faster (up to 50 FPS) for a quick flip through a stack.
3. Adjust Image Quality, Resolution, or Colors (Optional): Use Image Quality (%) to trade detail for a smaller file, set a Preset Resolution or Width x Height to resize every frame down from a 46 MP Merrill capture, or apply Color Reduction + Dither to shrink the palette.
4. Convert and Download: Click Convert and save your APNG. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No Sigma Photo Pro install, no sign-up, no watermark.

APNG vs GIF for Foveon Photo Frames

Frequently Asked Questions

How do I combine multiple X3F files into one animated APNG?

Add every X3F you want as a frame before you convert — the upload order is the playback order. Each Sigma RAW file is demosaiced to an sRGB frame and stacked into one APNG, with the Framerate setting controlling how long each frame is shown. A single uploaded X3F produces a valid one-frame (static) APNG, which is just a normal PNG with animation metadata that any viewer falls back to.

Why pick APNG over GIF for Foveon photos?

The whole point of the Foveon X3 sensor is clean per-pixel color, and GIF throws most of that away by capping every frame at 256 colors, which adds visible banding to skies, skin, and smooth gradients. APNG stores full 24-bit color losslessly, so the frames look like the demosaiced original. In our testing, a 5-frame bracket from an SD Quattro produced an APNG with no posterization where the GIF version dithered across the sky.

Will my APNG keep the full Foveon detail and bit depth?

The X3F is demosaiced and rendered to 8-bit sRGB frames before being packed into the APNG, so you keep the full color and resolution of the capture but not the 12-14 bit RAW latitude. APNG itself is lossless, so it does not re-compress the frames the way GIF does — it preserves whatever the rendered frame contains unless you lower the Image Quality (%) slider. If you need the full editing headroom, keep the X3F as your negative and export X3F to TIFF instead.

Which browsers and apps play APNG files?

Chrome 59+, Firefox 3+, Safari 8+, Edge 79+, and current Opera play APNG natively — about 94.7% of users worldwide per caniuse. In an app or old browser that does not support it, the file falls back to showing its first frame as a normal still PNG, so it never appears broken — it just stops animating.

Does the converter need Sigma Photo Pro to read my X3F?

No. The conversion runs an open-source X3F decoder pipeline on our servers, so you don't need Sigma Photo Pro installed to demosaic the Foveon data. Very early SD9/SD10 files and some Quattro-specific metadata are less battle-tested than they are in Sigma's own software — if you see a color shift on those frames, render them in Sigma Photo Pro first, export to PNG, then build the APNG with PNG to APNG.