What is the banding in my sky?

I took this this morning with my 5D2 and 24-105. What is the weird banding in the sky? This is OOC except for some niose reduction and resizing. It's hard to see, but it's there. Seems to be coming from where the sun was rising...

Shot in JPEG?, you only have 256 shades of blue. When the sky is intense, uniform, and strongly peaked at a particular wavelength, you are going to see banding.
May be of interest too:

A Few Thoughts on Banding in Images

How to Stop Banding in Your Images

Quad-Response wrote in post #13629637
Shot in JPEG?, you only have 256 shades of blue. When the sky is intense, uniform, and strongly peaked at a particular wavelength, you are going to see banding.
May be of interest too:

A Few Thoughts on Banding in Images

How to Stop Banding in Your Images

Interesting! Yes, I did shoot in jpeg (forgot to change my settings) and then did my regular noise reduction. I shoot lots of sky, and never noticed this before, but I just got the 5D2 and before was using the 50D. Am I seeing it more because of the increase in megapixels, the move from crop to full frame, or maybe both?

Thanks for the links - I"m headed to add some noise back and see what that does...

Jpeg compression artifacts can show up in skies a lot, yes. So, a first question would be is the banding showing up when you view your image full-size, as in at 100%? If you shot in a Large, Fine jpeg I'd think not.

But, of course, when you resize and save to a small jpeg, then the results can easily be as you have seen. As to how to minimize the problem, well, maybe those links will provide the answer!

Add a bit of noise, and the banding will probably be gone