Damien Symonds

Possibly because you uploaded PNG files. Have you also tried Jpeg? Most likely it's just an unavoidable Facebook thing. I can't see any banding in these files you've posted here. Can you?

By the way, please read.

Beautiful. Now, you should find that the "Colour Fix" layer from The Handyman Method will work fine for this.

There's nothing worse than doing elaborate Photoshop work, THEN realising you have to start over because you messed up your raw processing. I want to protect you from that pain. Please follow the noise removal link that Christina provided earlier, so we can be content in the knowledge that the raw processing is completed, and then we can get stuck into the PS work.

No, it's really awful. Sorry

No, still noisy

Your master file. Your PSD. You didn't crop it, did you? http://www.damiensymonds.net/2011/09/cropping-tutorial.html

Ok, that's a bit too loose. That's a bit more of the lady than is possible to clone out.

Please don't do any Photoshop work until your raw processing is done.

Much better, well done.

Thankfully, the shadows are falling on the other side, the side where you don't need to replace the wall.

This is the best I can manage. Would it be ok?

RGB is not a colour space, it's a mode.

It's a coating they put on the lenses. I'm really struggling with this one. There are some more things I want to try, but it'll have to wait til tomorrow, sorry.

It looks like you've used a linear gradient instead of a radial one?

Are you familiar with this? http://www.damiensymonds.net/2010/10/shift-while-brushing.html

Oh gosh, it's really severe, isn't it? Did you shoot raw?

Yes, it's incredibly destructive. Never use it. Only use the Crop Tool, and NEVER during editing. http://www.damiensymonds.net/2011/09/cropping-tutorial.html

NEVER use the Free Transform method. It's a very dangerous myth.

Great. Follow all the troubleshooting steps in my tute.

Which calibrator do you have?

No, sorry, I'm not taking on editing work at the moment. Does this help? http://www.damiensymonds.net/preventing-banding-in-backdrops/

Yes, essentially it's a laptop screen.

Download the PSD It's the same gradient layer twice. The bottom one is on "Multiply" mode, and I kept it hidden until I'd almost completely masked the top one. Then I painted on its mask at low opacity to darken the background around the hair just enough to match the new background. And the top layer is the noise layer.