Camera Raw 18.6 – Local Mask Sharpening/NR values become incorrectly shared between saved ISO presets

Camera Raw 18.6 – Local Mask Sharpening/NR values become incorrectly shared between saved ISO presets

I believe I have found a reproducible bug in Adobe Camera Raw when used directly through Photoshop.

Environment

• Photoshop 27.10

• Adobe Camera Raw 18.6

• Testing performed directly through Photoshop → Camera Raw, not through Bridge or Lightroom.

Important troubleshooting already performed

I purged the Camera Raw cache and deleted relevant .xmp files between tests as necessary, so I was starting each test from as clean a state as practical. The problem remained reproducible.

Reproduction

1. Create an ISO 1600 LNR+MASK preset with:

   • Local Background Mask Sharpening = −10

   • Local Background Mask Noise Reduction = 40

2. Test the ISO 1600 preset on multiple different ISO 1600 photos.

   • All photos correctly receive −10 / 40.

3. Create a second ISO 3200 LNR+MASK preset with:

   • Local Background Mask Sharpening = −20

   • Local Background Mask Noise Reduction = 60

4. Test the ISO 3200 preset on multiple different ISO 3200 photos.

   • All photos correctly receive −20 / 60.

5. Return to other ISO 1600 photos and activate the ISO 1600 LNR+MASK preset.

   • The global Sharpening/Detail/Masking settings are correct for ISO 1600.

   • However, the Local Background Mask now incorrectly shows −20 / 60, which are the Local Mask values from the ISO 3200 preset.

The problem can also occur in the reverse direction:

6. On an ISO 1600 photo, manually restore the Local Background Mask to −10 / 40.

7. Open the photo as a Smart Object and immediately close it, without intentionally making or saving any additional changes.

8. Return to ISO 3200 photos and activate the ISO 3200 LNR+MASK preset.

   • The Local Background Mask now incorrectly shows −10 / 40, which are the values from the ISO 1600 preset.

Observed behavior

The two presets initially work correctly on multiple different photos. After switching between the presets, however, the Local Background Mask Sharpening and Noise Reduction values can be incorrectly replaced by the corresponding values from the other ISO preset.

The important distinction is that the global Sh/R/D/M settings remain correct and independent. The apparent cross-contamination is specifically occurring with the Local Background Mask Sharpening and Noise Reduction settings.

The behavior is reproducible in both directions:

ISO 1600 −10/40 → ISO 3200 −20/60

can subsequently result in:

ISO 1600 incorrectly loading −20/60

and changing/restoring the ISO 1600 Local Mask can subsequently result in:

ISO 3200 incorrectly loading −10/40

This appears to be a problem with how Camera Raw saves and/or retrieves the Local Mask settings associated with different presets.

I would appreciate it if the Camera Raw team could investigate this behavior.

I have attached 3 jpeg showing the above sequence creating the two ISO Pesets , and the 3rd jpeg shows the corrupted ISO 1600 Preset with the  values from ISO 3200 preset

I was working in Win 11 with PS - ACR directly