As you know, when you are in the Finder, you can select a picture file then press the space bar and be presented by the image in full detail. This is the Quicklook functionality.

Prior to Monterey, on my Mac, if I chose a Raw file, Quicklook presented me with a rendered image of this Raw file.

For example if I had shot with my camera in Raw + Jpeg, I would have two files, one raw and one jpeg. Quicklook would not present me the same image. On the jpeg file it would be the 8-bits compressed jpg, on the Raw, it would be a rendering with Apple own rendering engine of the file, with more color depth.

Not anymore on my Mac under Monterey.

Quicklook now presents me with the same image on both files. I have made a test by shooting "black an white" and Quicklook on the raw file is black and white.

This is a high suspicion that Quicklook is now presenting me by default the compressed jpeg that is stored inside the raw file (including the treatments asked at shooting, here, black and white).

However, if I zoom inside Quicklook on the image, the raw is now charged (as evidenced by the fact that it is now in color).

[For clarification, the usual structure of a Raw file includes the raw data received by the sensor, hence in color, and a compressed jpeg of the raw data, half size in the case of Canon, and visibly here including the B&W post processing].

I've shared this info with one person that does not see this behavior.

So I'm coming here to clear the debate: Is presenting a compressed jpeg on a raw file the now default functionality of Quicklook ?

And if not, my Quicklook might be broken, any idea to recover it ?



The behavior persists if I use

qlmanage -p -g /System/Library/QuickLook/Image.qlgenerator -c public.image MyPicture.CR2

which forces Quicklook to use the Apple native quicklook module.

This seems to imply it is indeed a change in Apple policy

  • I don't know the answer, but I do know that QuickLook is intended to be a ... quick look. There are limits to the complexity and time of a QL component rendering an image. So it may be that some RAW files are too complex or too slow to be rendered by QL, and the JPG file is used instead.
    – benwiggy
    Commented Sep 8, 2022 at 13:15
  • It used to work before. Either I broke something in my configuration, or Apple decided to change the standard behavior, the increasing size of raw file and the complexity of rendering might be a reason
    – Hugues
    Commented Sep 8, 2022 at 14:36
  • The embedded JPEG is supposed to be a correct thumbnail of the RAW file. Quick Look will indeed load the embedded thumbnails when it can to save memory. (At least for thumbnails ; not sure about previews). Commented Sep 8, 2022 at 16:45


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