banding in sky

[doug anderson]

how to I get rid of banding in the sky?

[NotMyFault]

There are multiple aspects to consider.

1. if possible adjustment Camera settings to reduce sharpening.
2. Shoot in RAW format.
3. Sharpen selectively in Photo, excluding the sky
4. If using JPEG: you are limited to 8bit color channel depth. Using dithering is the easiest way. Make a selection of sky with brush tool, add „diffuse“ live filter and play a bit with settings (radius, protect alpha).
5. If able to use RAW and export to JPEGXL or other file formats capable of 12 or 16 bit, this will avoid banding. But beware: While using Affinity, the rendering is clipped to 8-bit for 16-bit color formats. You need to export and view the files with a more capable image viewer. Preview on Mac will do. Don’t know wich app is suitable on Windows (the OS default apps from Microsoft are not).
6. Please consider that the usual approach of adding a blur filter can actually increase the banding, at it will remove any noise or dithering.
7. the only way to use more than 8-bit color depth in Photo and see the result while editing is convert to RGB/32. which can use the full bit depth of your display (normally 8, 10, 12, or 14 bits in exceptional cases). But this has several drawbacks like file size, lower performance, depending on display, OS etc need to fully support HDR/EDR, calibration can be impossible or tricky, some filters won’t work, and need to export into „downgraded“ formats after editing.

There are other specialized apps who promise to remove banding automatically.