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Antonio26564936fcsh
Antonio26564936fcsh
Known Participant
March 29, 2026
Question

LR Classic 15.2.1 converts embedded B&W JPEG previews to color

  • March 29, 2026
  • 3 replies
  • 81 views

I’m using Lightroom Classic 15.2.1 on Mac with Canon R5 RAW+JPEG B&W.

I usually rely on embedded previews to see the JPEGs in B&W, but since I received a previews’s error when starting Lightroom today, LR gradually rebuilds all images in color.

When I access to any folder in my Lybrary module, LR starts rebuilding all my BW previews to color.

I’ve deleted Previews.lrdata, cleared the Camera Raw cache, and set previews to Low/1024, but it still converts thumbnails to color. I need a way to keep the JPEG B&W previews in Library without Lightroom regenerating them from the RAW.

Can someone help me to solve this?

Kind regards.

 

    3 replies

    johnrellis
    johnrellis
    Legend
    March 30, 2026

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    ​@Antonio26564936fcsh I already have Preferences → Presets → Raw Defaults → Camera Settings configured. However, Lightroom still starts rebuilding previews in color for every folder I open in my catalog.

    Select one of the photos whose preview gets rebuilt in color, go to Develop, and look at the Profile in the Develop panel. Is it the profile you set in Raw Defaults, or is it a color profile?  

     

    If it’s a color profile, then most likely the photo was imported with a different default profile. And when LR builds a preview, it’s a preview of all the current settings in Develop, including the profile.

    Antonio26564936fcsh
    Antonio26564936fcshAuthor
    Known Participant
    March 30, 2026

    I did that in my catalogue, and the Profile in the Develop panel is “Adobe Color”.

    I did the same test in the brand-new catalogue I created yesterday (that works correctly) and in Develop panel I can see the Profile as “Camera Standard”.

    ¿?

     

    johnrellis
    johnrellis
    Legend
    March 30, 2026

    [View this post in your web browser. It contains formatting and images that don't appear in email.]

     

    ​@Antonio26564936fcsh I did that in my catalogue, and the Profile in the Develop panel is “Adobe Color”. I did the same test in the brand-new catalogue I created yesterday (that works correctly) and in Develop panel I can see the Profile as “Camera Standard”.

    Since that photo in your main catalog has profile Adobe Color, its previews in Library will render in color.

     

    Most likely, you imported that photo into the main catalog before you changed the Raw Defaults to Camera Settings.  The Raw Defaults setting only applies to newly imported photos or when you click Reset, not to previously imported photos. 

    johnrellis
    johnrellis
    Legend
    March 30, 2026

    [View this post in your web browser. It contains formatting and images that don't appear in email.]

     

    Canon R5 RAW+JPEG B&W.

    An alternative to Johan’s solution: Set the option Preferences > General > Treat JPEG Files Next To Raw Files As Separate Photos. Future imports will import the .jpg files recorded by the camera as separate photos in your catalog.

     

    Note that these JPEGs are not LR previews of raw files -- they are JPEGs created by the camera at the time you pushed the shutter. 

     

    LR previews are renderings of the imported raw files that are cached in the catalog folder (as described by Johan).  LR initially uses the preview that the camera embedded in the raw file (different from the JPEG recorded as a separate file), and then renders each raw in background to produce a more accurate preview corresponding to the raw’s current develop settings.

    JohanElzenga
    Community Expert
    JohanElzengaCommunity Expert
    Community Expert
    March 29, 2026

    If Lightroom Classic builds its own previews, then it does so in accordance with the camera default settings (preferences - presets). If you set that to ‘camera settings’, then the previews should remain in B&W if you shot in B&W. If you’ve set it to something else, then Lightroom Classic will build previews in color, because the raw files are in color regardless of your shooting settings.

    -- Johan W. Elzenga
    Antonio26564936fcsh
    Antonio26564936fcshAuthor
    Known Participant
    March 30, 2026

    Thanks for your suggestion.

    I already have Preferences → Presets → Raw Defaults → Camera Settings configured. However, Lightroom still starts rebuilding previews in color for every folder I open in my catalog. Initially I see my photos in B&W, but gradually the thumbnails switch to color.

     

    I also tested opening one of my catalog backups from two months ago and the same thing happens, which makes me think it’s related to Lightroom configuration rather than a recent catalog change. However, I created a brand-new catalog on another disk, imported a new folder of photos, and it works correctly — thumbnails remain in B&W and are not converted to color.

     

    Any idea how I can fix this behavior in my main catalog, where I have thousands of photos?

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