Reference Formats
CR3
Canon's current RAW format, built on the ISO Base Media File Format (the MP4/HEIF container family) rather than TIFF, adding native lossy C-RAW compression and support for Dual Pixel RAW data.
Extension
.cr3
Full name
Canon Raw Image 3
Introduced
2018, with the EOS M50 and EOS R
Vendor
Canon
What is inside the container
Unlike CR2's TIFF structure, CR3 is an ISO-BMFF/MP4-style container that holds sensor data compressed with Canon's CRX codec (a hybrid of JPEG-LS and JPEG-2000 techniques), an embedded JPEG preview, full Exif/MakerNotes, and, on some models, focus and scene-recognition data alongside optional Dual Pixel autofocus information. The container change was significant enough that third-party raw processors needed genuinely new parsers rather than incremental updates, which produced a well-documented support lag through 2018-2019.
How to open it
For archives
Because CR3's ISO-BMFF container is different enough from older TIFF-based RAW formats that some legacy tools and DAM raw-preview plugins still can't parse it, explicitly verify a DAM's rendering engine supports CR3 rather than assuming generic "Canon RAW" support covers it. Converting to DNG remains the safest long-term archival hedge given the format's relative youth and the compression-codec dependency.
Canon introduced CR3 in 2018 alongside the EOS M50 and EOS R, its first mirrorless bodies built around a genuinely new raw container rather than an update to the CR2/TIFF lineage. CR3 is based on the ISO Base Media File Format — the same family used by MP4 video and HEIF images — and adds Canon’s CRX codec, a mix of JPEG-LS and JPEG-2000 techniques, giving it both lossless RAW and a lossy C-RAW option that shrinks files 30-50% versus CR2 at a similar image.
The container switch mattered in practice: because CR3 isn’t structurally a TIFF file the way CR2 and most other manufacturers’ RAW formats are, third-party software needed to write new parsing code, not just add another camera model to an existing decoder. Adobe added CR3 support to Camera Raw 11.0 and Lightroom Classic 8.0 in late 2018, but other Adobe tools, notably Bridge, lagged into 2019, and community forum threads from that period document real frustration among photographers unable to browse CR3 files in tools they’d relied on for CR2. For a DAM, that history is a caution: don’t assume a raw-preview integration that handles Canon RAW in general actually handles CR3 specifically, especially in older or less actively maintained DAM deployments.
Frequently asked
Why can't some older DAM raw-preview plugins render CR3 files?
CR3 uses an ISO-BMFF/MP4-style container instead of CR2's TIFF structure, a change significant enough that third-party raw processors needed genuinely new parsers, producing a documented support lag through 2018-2019 that some legacy tools never closed.
What compression does CR3 use that CR2 didn't have?
CR3 introduced Canon's CRX codec, which enables native lossy Compressed RAW (C-RAW) alongside the existing lossless RAW mode; CR2 only ever supported lossless compression. CRX blends JPEG-LS-style Rice-Golomb and run-length entropy coding with a JPEG-2000-derived LeGall 5/3 wavelet transform, then quantizes the wavelet coefficients to shrink files roughly 40% versus lossless RAW. For a DAM archive, this means CR3 assets may arrive already lossy-compressed by camera settings, which matters when documenting preservation-master fidelity.
Should a DAM assume generic Canon RAW support covers CR3?
No. CR3 replaced CR2's TIFF-based structure with an ISO Base Media File Format container, the same family used by MP4 and HEIF, so a decoder built around classic TIFF-EP RAW parsing will not automatically read it. Before onboarding Canon assets into a DAM, verify the rendering engine or embedded SDK lists CR3 explicitly, ideally with the specific camera model, since some libraries added TIFF-based Canon RAW support long before CRX-compressed CR3 files existed and never backfilled it.
When did Adobe add CR3 support?
Adobe added CR3 support with Camera Raw 11.0 and Lightroom Classic 8.0, released in October 2018 alongside the Canon EOS R, several months after CR3 first shipped with the EOS M50 earlier that year. Other Adobe apps lagged further: Bridge's thumbnail and preview generation for CR3 files wasn't fully reliable until updates arriving in 2019. For a DAM pipeline built on Adobe's SDK, this gap means CR3 previews and metadata extraction for cameras released between the M50's launch and October 2018 may have been unsupported at first.
What extra data can CR3 carry that older Canon RAW formats don't?
Beyond the standard Exif/MakerNotes block and embedded JPEG preview that CR2 already carried, CR3's ISOBMFF container adds dedicated boxes for autofocus data: on supported bodies this includes per-pixel Dual Pixel AF information and focus/scene-recognition metadata that Canon's own software uses for AF-point review and refocusing tools. This structured AF payload lives in Canon-specific CR3 boxes rather than standard Exif tags. For a DAM, this means CR3 files may hold richer focus metadata than CR2, but only parsers built to understand Canon's box structure, not generic Exif readers, can extract it.
What is the safest long-term archival hedge for CR3 given the format's youth?
Converting to Adobe's DNG remains the safest long-term archival hedge for CR3: DNG is openly documented and, as of March 2026, formally standardized as ISO 12234-4, giving it a durability guarantee CR3 lacks, since CR3 depends on Canon's proprietary, only reverse-engineered CRX compression codec. Storing DNG alongside, or instead of, the original CR3 reduces the risk of a future decoder gap if Canon changes CRX or a DAM's rendering library drops support. Keep the original CR3 too when storage allows, since DNG conversion, lossy or lossless, is itself a transformation of the source data.
When was CR3 introduced and on what cameras?
CR3 was introduced in 2018, launching first with the Canon EOS M50 (announced February 2018) and shortly afterward with the full-frame EOS R that autumn; it replaced CR2 as Canon's default RAW container going forward. Canon subsequently rolled CR3 out across its APS-C and full-frame lines, including the EOS RP, 90D, M6 Mark II, M200, 250D, and later R-series bodies, while CR2 continued only on older or lower-tier models still in production. For a DAM, this means Canon assets from cameras released after early 2018 are increasingly likely to arrive as CR3 rather than CR2.
What open-source tool added CR3 support after launch?
RawTherapee, the open-source RAW processor, added CR3 decoding in version 5.8, released in February 2020, roughly two years after the format launched with the EOS M50; earlier RawTherapee releases could not open CR3 files at all. The delay reflected how long it took the open-source community to reverse-engineer Canon's undocumented CRX codec and ISOBMFF-based container, work that also underpins libraries like ExifTool and LibRaw. For a DAM relying on open-source decoding, this history is a reminder that new proprietary RAW formats can outpace community tooling for a year or more.
Sources
- Canon introduced the CR3 format in 2018 with the EOS M50, and it is now standard across the EOS R lineup. checked 2026-08-07 — FileInfo.com - CR3 File
- CR3 files are stored using the ISO Base Media File Format (ISO/IEC 14496-12) with custom Canon tags, and include the Canon CRX codec combining JPEG-LS and JPEG-2000 techniques; C-RAW (lossy) can reduce file size 30-50% versus CR2. checked 2026-08-07 — FileFormat.com docs - CR3 File Format
- As of April 2019, Adobe Bridge still did not support CR3 raw files from the Canon EOS R, EOS RP, and EOS M50, despite Camera Raw/Lightroom support arriving earlier. checked 2026-08-07 — Adobe Community forum thread - CR3 not supported in Adobe Bridge 2019