P: New File with .ACR extension when saving Camera Raw settings

[Coma004]

Hello Community,

I used ACR in version 13 and upgraded to version 14 as it was available. When editing pictures in ACR, I was used to see .xmp files when saving my changes for the edited pictures - this file contains the settings I made according to the raw file. Now, there is an additional file with the extension .ACR. I can't find any info on this type of file or for what it is used. Can someone tell me?

[Rikk Flohr: Photography · Accepted solution]

The .ACR file contains the pixel versions of previously generated AI masks (Select Subject/Sky) so they don't have to be recalculated each time you open a raw file with previous AI masking elements.

[Lumigraphics · Accepted solution]

And it appears that a separate sidecar is needed because XMP is XML (plain text) and .acr is a binary file.

[Coma004]

Thank you very much for the answer, this makes sense because I used the AI masking feature before.

[Michael Arellano]

Rikk, as far as I can tell, Lightroom Classic (latest version with Adobe Creative Cloud) does not produce these .acr files when using AI masks. Where is that data stored instead? I'm curious because I'm now having issues re-naming my photos after editing them with AI masks in Camera Raw (again, latest version with Adobe Creative Cloud, 14.0.1), which produces these new .acr files but Photo Mechanic does not re-name the .acr files, only the .XMP files.

[Rikk Flohr: Photography]

The .acr files are only used in Camera Raw.  Masks in Lightroom Classic are stored in the yourcatalogname.lrcat-data file which lives  along side your .lrcat catalog file. 

[mikeb28930794]

Just upgraded to PC CC 2022 (V23) yesterday (too many projects going on to repeat previous upgrade debacles). I have a workflow where I scan film negatives to DNG files using Silverfast 8.8 (48-bit raw). When I open the file in ACR and change image settings (apply a profile, apply geometry and crop tools) then open to PS, ACR leaves a file behind with the extension ".ACR".  ACR settings have "DNG Handing" set to "Always use Sidecar XMP files." This file extension doesn't seem to be documented anywhere and I cannot find it searching in this forum (search ".acr" returns every ACR post since dirt).

These file are small, and not necessarily troublesome, but I am trying to understand why and what is being left behind on my drive.

[TheDigitalDog]

See: https://community.adobe.com/t5/camera-raw-discussions/camera-raw-generates-acr-files-when-editing/m-...

Rikk Flohr: Photography • Adobe Employee , Mar 29, 2022

A .acr file contains non-textual data (binary). Currently that can be an AI-generated pixel-based mask and/or a LUT. Other items will be stored in this file in the future.  I am guessing your color preset has a profile that uses a LUT (look up table). 

Not a bug.

[mikeb28930794]

Uh, the pointed to post, ".ACR file contains the pixel versions of previously generated AI masks (Select Subject/Sky) so they don't have to be recalculated each time you open a raw file with previous AI masking elements." None of the edits have used masks. But then, there are no bugs in Adobe, only features.

[TheDigitalDog]

You asked what these files are, you were told. You state “This file extension doesn't seem to be documented anywhere” but it has been.

You state : “None of the edits have used masks.”

Did you see the explanation: “and/or a LUT”?

So now you're telling us the files are the result of a bug?

[mikeb28930794]

Quite the contrary. I clearly stated that there are no bugs in Adobe code.

[TheDigitalDog]

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@mikeb28930794 wrote:

Quite the contrary. I clearly stated that there are no bugs in Adobe code.

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You can thank Adobe’s great team and prerelease testers.

You are welcome. 😘

[melajuana]

Weird I didnt start getting ACR sidecars until this last update only xmp despite editing in ACR