Remove banding from sky gradient

I've shot raw for many years with a Canon 5DII & 5DIII.  Only recently, I've noticed that I'm getting subtle banding in the blue sky gradients in some of my images.  This is prior to any sizing, processing, sharpening, conversion to 8 bit, etc.  that might cause that to appear.  These are in the initial raw files I open.  Previously, I've used LIghtroom/PS CS5 & CS6 with no issues.  I'm now using Lightroom & Photoshop CC (the latest releases) & set the color profile to Pro Photo RGB for the files upon opening.  Has something changed with the CC versions of these programs to make that more prevelant?  

Does anyone have a good way of removing this banding without having to resort to adding grain or noise to the image?

Thanks for any advice!

I haven't seen this using the same gear and sw, Wick.

Any chance it was caused by polarizer with wide angle lens?

Wick,

If the sky is clear, i.e. no clouds or other detail, you could try this in PS-CC after converting an unadjusted RAW:

Do the following before making any other adjustments to the image.

1. Create a copy of the background layer.
2. Select only the sky
3. Create a layer mask on the background copy
4. Choose Filter>Blur>Gaussian Blur
5. Choose the amount of blur in pixels; try a low value, say 10px. Click OK.
    

If 10px doesn't achieve the results you want, delete the blur history state and then try again with a higher value.

I am not truly certain this work, and I hope someone will chime in with a better solution for you.

--P 

Lance,

I did not have a polarizer in place for any of the shots with banding, so that's not it.  Nor were there any other filters used such as ND filters.  I will say that it seems to occur when I'm shooting a darker sky, such as twilight.  I don't see it in the lighter daytime skys.

Thanks,  Wick

It might be helpful for us to see an example. I assume that what you see is posterization (banding usually refers to a sensor issue where adjacent lines of pixels produce non-identical brightness, leading to the appearance of a fine line pattern), which usually results from large brightness or contrast adjustments. It is unusual for it to appear in unprocessed RAWs. What color depth is your monitor set to?

Wick, I'm not sure it's the same thing, but I often see banding in PS6 when I'm working on images.  However, when I export that image or go to a zoomed view the banding goes away.  I believe that its photoshop (or lightroom) downsizing an image for screen display and not in the actual image.

which usually results from large brightness or contrast adjustments.

I do not shoot digital, so no RAW file per se, but the above comment will bring on banding for me in post processing. However, after finding out my faults I quit the procedure I was using and have not had the issue in quite a few years now.

I think I've used the Choose Filter>Blur>Gaussian Blur process Preston outlines with some success in the past, as well as the addition of noise and or dust, scratches & despeckle removal at times.

Obviously the idea is to find out the cause to prevent the need for fix. Good luck Wick in finding the problem.  

I think I found answer to the remove of the banding in the sky.  I'm only getting banding when I'm taking shots around twilight & the gradient in the sky is dark & very subtle.  Even when zoomed to 100%, the banding is still evident.  Here's the fix I implemented:

1) I used the Effects panel in Lightroom.  I added grain to the image with these settings: Amount=8, Size=0, Roughness=0.  I played with the lowest possible levels for these that would eliminate the banding.  These settings seemed to work well.  It adds a bit of grain or noise to the image.  

2) I exported the image to PS for editing, and used Nik Define 2.0 to remove the grain/noise I added in Lightroom.  The banding did not re-appear after the noise reduction

I don't know if this will work for anyone else, but it solved my problem.

Thanks for all the suggestions.