Updated October 14, 2026. Written for LightCraft 0.7.1 (what changed since).
Which CR3 files open in full
CR3 is a container, and Canon packs several kinds of image into it. Whether LightCraft can develop a file depends first on the raw setting you shot with:
| What's in the CR3 | What you get | Notes |
|---|---|---|
| RAW (lossless) | Full decode from the sensor data | Canon's standard RAW setting |
| C-RAW | Full decode from the sensor data | Canon's smaller, lossy-compressed raw. Both C-RAW versions decode, except files split into several tiles |
| Dual Pixel RAW | The main image decodes | The extra dual-pixel data is ignored |
| Other CRX coding variants | Embedded preview | Vertical tiles, partial subbands and multi-tile files are refused by the decoder |
| Reduced-size CR3 (sRAW, mRAW) | Embedded preview | Only the four-plane Bayer layout is decoded |
| HEVC tracks (HEIF, HDR PQ) | Embedded preview | Recognised in the file but not decoded |
Bodies matter for one reason: only some have been checked on real files. LightCraft's developers have confirmed the decode on the EOS M50, EOS R100, EOS R8 and EOS R5 Mark II (including its crop mode), and report the EOS R7 working. The R5, R6 Mark II, R50, R10, 90D, M50 Mark II, PowerShot G7 X Mark III and the rest of Canon's CR3 cameras go through the same decoder without that check, and the developers put the chance of a clean decode for such a body at about 60%. Their camera coverage list has every model.
Older Canon files are simpler. CR2, from Canon's older DSLRs, decodes in full, including sRAW and mRAW. CRW files from the early 2000s show the embedded preview.
Open a CR3 file, step by step
- Open the editor. The first visit downloads about 20 MB, then a library with demo photos appears.
- Drag the .CR3 files from your file manager onto the LightCraft window. The File › Import Photos… picker doesn't list CR3 among its file types, so dragging is the quick way in.
- Each file is copied into the library in your browser and gets a thumbnail in the grid. Look at the bottom-left corner of each thumbnail: an amber Preview pill means LightCraft is showing the camera's JPEG for that file.
- Select a photo and press E. A preview file shows a "Preview only" notice in the panel that names the CR3 variant it couldn't decode. A file that decoded in full has no notice.
- Develop, then export with File › Export… (Shift+E). JPEG, PNG, TIFF and WebP arrive as normal browser downloads.
When a CR3 opens as "Preview"
You can still rate, crop and adjust a preview file, but the sliders work on the camera's JPEG. Its white balance and picture style (Monochrome, for example) are already baked in, highlights clipped by the camera stay clipped, and the export can't be better than that JPEG. For a quick look or a share, that is enough.
For real raw development, convert the file to DNG. Adobe's DNG Converter is free for Windows and macOS and reads the CR3 variants Camera Raw supports. Drag the resulting .DNG into LightCraft: DNG decodes in full, and LightCraft takes its colour from the matrices stored in the DNG instead of estimating it from the preview.
For the next shoot, check the camera's raw setting. Standard RAW and C-RAW are the two that decode. Reduced-size raw and HEIF capture fall back to the preview, and so do some CRX variants whose cameras haven't been identified yet.
Installing the desktop LightCraft doesn't help here: it uses the same CR3 decoder as the browser build, so a preview file stays a preview.
Colour and framing from a CR3
LightCraft has no measured colour profile for any Canon body yet. For a CR3 it fits its colour to the JPEG preview in the same file, and accepts the fit only when it passes a set of checks; if it fails, the photo starts from a neutral matrix and comes out darker and much less saturated than the camera's JPEG. Set white balance with the eyedropper on something grey, then raise Vibrance or try the Vivid profile. The full story is in the project's CR3 notes.
Framing follows the camera. If you shot 16:9 or 1:1, the developed image comes out in that shape. The thumbnail of an unedited raw is the camera's embedded preview, which shows the whole sensor, so it can look wider than the photo you open. Lens distortion is not corrected automatically, because LightCraft has no lens profiles of its own. Wide-angle shots that Canon's JPEG straightens will look more curved; the Optics panel has a manual distortion slider.
Keep the originals where they are
Importing copies each CR3 into your browser's storage for this site; your original stays on your disk or card. That copy is what lets the library and your edits survive a restart, but clearing the site's data deletes it. Use File › Back Up Library… once you have edits worth keeping, and work in one tab at a time.
Developing a whole Canon shoot to JPEG works the same way as for Nikon and Sony files: the NEF and ARW to JPG guide covers batch export, and editing RAW photos online covers the develop panels. If someone sent you a CR3 alongside other unfamiliar files, the Craft apps hub has a list of which app opens which file.
Start with one file: drag a CR3 in and check its thumbnail for the Preview pill before you import the rest of the card.