FastRawViewer 1.5.1: Canon CR3 format support

Finally, the support for Canon CR3 format!

Camera support

  • Canon: EOS R, EOS RP, EOS M50, PowerShot SX70 HS, EOS 250D (preliminary support)
  • Leica D-LUX7, Q2
  • Panasonic DC-G90/95

Kudos to Alexey Danilchenko for figuring out the CR3 format!

FastRawViewer 1.5.1

Minor changes

  • Prior to version 1.5.1, FastRawViewer always creates XMP sidecars with .xmp (lowercase) extension. File extension case (upper/lower/mixed) does not matter for most cases because widely used filesystems are not case sensitive. However, latest version of Windows 10 could support case sensitive filesystems (this should be enabled explicitly on per-folder basis), also Mac OS/macOS has case sensitive option.

    As a temporary solution FastRawViewer 1.5.1 implements limited additional case in-sensitivity for XMP sidecars:
    • if .xmp file is not present for given RAW file
    • but .XMP file is present (e.g. created by some other software)
    •  than .XMP one will be used for all operations with given file (metadata store, copy/move).

    If both files are present, the .xmp (lower case) one will be used. We are watching user feedback and possibly will make a more flexible / convenient solution (for example, explicitly specifying a register in the settings) in the future, if users will request it.

  • New setting: Thumbnail cache - Disk thumbmail cache - Use disk thumbnail cache for:TIFF and PNG files or All files.
  • removed misleading "(raw decode only)" comment for Sigma cameras in built-int supported camera list.
  • The Enable/DisableFoldersRefresh hidden setting is now visible as Preferences - Other - Refresh folders tree after file copy or move. To refresh subfolder list in Folders panel (if automatic refresh is off) use Refresh subfolder list item of right-click menu (right-click on folder name).

Bugs fixed

  • Fujifilm DBP for GX680: internal JPEG previes were displayed incorrectly
  • Preview were not extracted for some DNG files



When viewing internal JPG, the displayed image is incorrect.

Dear Sir:

Thank you, we will fix it.

Fixed in version 1.5.1-1485


Alex Tutubalin/FastRawViewer team

Will you publish the code source to decode crx compression in Libraw ?
Kind regards,
Laurent (

Dear Sir:

Yes, when ready.

Please ask LibRaw-related questions at LibRaw forum,

Hey all, please tell me how to display cr3 thumbnails viewer. tks

FastRawViewer supports CR3 format including thumbnail display


Alex Tutubalin/FastRawViewer team

Will you / are you working on a version for Linux?

No such plans for foreseeable future.


Alex Tutubalin/FastRawViewer team

When will you have a fix for Canon 1dx Mark III?

Dear Sir:

Lossless CR3 files recorded by Canon EOS-1D X Mark III are nothing new, no fix is needed. The should be fully supported in

To support lossy CR3 CRAW v.2 files recorded by Canon EOS-1D X Mark III we need full development cycle, and not a fix. That will take time.


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