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

Thanks for that. Actually it was my post on the exiftool forum. :-)

I've confirmed that turning off HDR PQ as a workaround allows for successful thumbnail generation in Sequoia 15.1 Below is a screenshot of the image's info window from Preview. Typically, I mostly retain HEIC files on the computer. HDR PQ doesn't seem to trigger the thumbnail issue with HEIC images. However, I often like to keep a few CR3 images for comparison or fine tuning. For the time being, these will need to be stored in a Zip archive to avoid excessive CPU consumption related to thumbnails (I suspect that it may be due to HEVC encoded previews in CR3 images taken with HDR PQ enabled).

- Pie Lover

P.S. Creating a custom CR3 Finder icon doesn't seem to prevent the excessive CPU issue in 15.1

Here's an alternative to placing (HDR PQ) CR3 files in a Zip archive to avoid the thumbnail issue...

Adobe's DNG converter (see below) can be used to convert a CR3 file to a DNG. Further, via a preference option, the RAW file itself can be embedded in the DNG for later extraction. An advantage of this approach is that the Sequoia (15.1) thumbnail extraction works without issue for DNG files so that the image can easily been identified in Finder or viewed in Quick Look. Note that DNG RAW files can be edited with macOS Photos and (of course) are supported in Adobe Creative Cloud apps.

A disadvantage is that the DNG file (with embedded CR3) will require about twice the storage of the CR3 file.

- Pie Lover

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

You can simply logout and back in or use the Activity Monitor to force quit the ImageThumbnailExtension process. For the time being, try zipping your CR3 (and possibly other types of RAW images) to prevent thumbnail generation for those images formats.

The problem with moving and deleting files is caused by the excessive CPU used when the ImageThumbnailExtension presumably executes in a tight, endless loop. The root cause may be that CR3 image shot with the HDR PQ option have embedded HEVC encoded previews (rather than JPEG). Turning off the HDR PQ option should allow the thumbnail generation to work normally (since thumbnails are likely generated from the embedded preview).

I reported the issue to Apple Support so, with any luck, it should be fixed in a future maintenance update.

- Pie Lover