Moire pattern on wall

[donp30872227]

I recently did finishing work on some files of a hotel for one of my clients. On a few of the walls appeared what looks like a moire pattern in the processed images. I use Lightroom for processing prior to retouching the files. This pattern doesn't show up in the original JPEG files sent to me by the client. I have no idea what created this pattern. I didn't do anything different than usual in my processing. Any thoughts or suggestions are appreciated. See attached photos.

[Lumigraphics]

Its in the originals

[donp30872227]

I have discovered that this pattern was created by one of my sharpening steps in an action that I use. Thanks for the comments and suggestions.

[Michael Bullo]

Good to hear you found the solution. Any chance you could post a little more detail that could help others with a similar issue?

FYI: The Camera Raw Filter contains Moire Reduction capabilities.

[donp30872227 · Accepted solution]

Yes, the specific step that created this pattern is called a "Defog" action from another photographer. Spcifically it's unsharp mask, amount 20%, Radius 40 pixels, Threshold 0. These files are created by HDR and often appear to have a bit of haze or flair. This was supposed to reduce that effect but it unfortunately caused the banding issue. Thank you for your comment.

[donp30872227]

I meant flare not flair. Sorry.

[Michael Bullo]

Thanks for the update.

If you aren't familiar with it, I strongly recommend exploring the Camera Raw Filter. If you are looking to "Defog" an image I think you'll find the Dehaze slider particularly powerful.

Be sure to turn your layer(s) into a Smart Object before applying a filter. That way you apply these changes non-destructively and can easily change them later.

[D Fosse]

To me this looks like banding, not moire. Banding happens in 8 in color depth, and the jpeg format is partucularly susceptible because the jpeg algorithm compresses the color component much more aggressively than the luminance component.

If you need to do further work on a jpeg, resave it as a 16 bit PSD or TIFF immediately.

Even better, ask your clients for TIFFs or PSDs to begin with.

[donp30872227]

Thank you for the suggestion. I'll keep that in mind for future work.