Missing QuickLook thumbnail for supported (Canon R Series) camera RAW file type (Sequoia)

Thanks for that. I didn't think it would matter, but my model is the original EOS R5 (Mark I). What's a bit frustrating is that CR3 thumbnails worked perfectly in Sonoma. I've only seen this before macOS added RP and R5 support and, more recently, with Sequoia 15.1.

For the time being, I'll add custom Finder icons to CR3 image (see https://discussions.apple.com/thread/253665893).

- Pie Lover

Just a thought but what firmware version was the R5 using when it captured this CR3 image that produces the thumbnail. One of my CR3 images that is missing a thumbnail was captured with firmware version 1.8.1 (I'm currently using version 2.1.0).

I downloaded some older online CR3 files captured with firmware version 1.3.1 and they seem to work as expected (see below). My theory is that CR3 images taken with more recent R5 firmware are not compatible with the thumbnail generation in Sequoia 15.1. Does this make any sense?

- Pie Lover

I believe that the screenshot below provides a plausible explanation of why different users are experiencing different behaviour. It hinges on changes to CR3 metadata in different versions of the R5 firmware (see screenshot below).

My suspicion is that Apple thumbnail works with CR3 files generated by older versions of the R5 firmware (e.g. 1.3.1) but not with more recent firmware (e.g. 1.8.1 and later). Further, when the ImageThumbnailExtension process (responsible for thumbnail generation) encounters such an incompatible CR3 file, it can result in high CPU consumption (e.g 100% on each of the 4 Performance cores on a Mac mini M2) which, in turn, can negatively impact macOS services.

Hope this provides some possible insight for this issue.

- Pie Lover

P.S. CR3 files generated by the earliest R5 firmware (e.g. 1.0.0) may not even be recognized as a valid macOS image file format

The Eclectic Light Company site has several articles about QuickLook (see for example: How Sequoia has changed QuickLook and its thumbnails).

It's possible that On1 has not updated their software to conform to the QuickLook API changes in Sequoia. Also, are you certain that changing the default app will automatically change the icon associated with the original file type? The icon typically changes when you explicitly change the actual file type (e.g. by changing the file extension).

- Pie Lover

[Edited by Moderator]

BTW, zipping all CR3 files created by recent R5 firmware and then deleting the original CR3 images avoids the excessive CPU issue associated with thumbnail generation (in Sequoia 15.1).

Hopefully, Apple will address this issue in an upcoming Sequoia maintenance update.

- Pie Lover

Thanks for the replies. I experienced the problem with the CR3 RAW file format used by the EOS RP and EOS R5. Both cameras have been supported by macOS for some time.

- Pie Lover

Thanks that's very interesting. I wonder what's different in my environment. I'll try copying a test CR3 file to another user account on the same machine.

- Pie Lover