Banding/posterisation problem I cannot fix.

Question

Hi, I am currently experiencing extremely bad banding in photoshop.
I've used photoshop to paint for many years (I'm a production artist for children's television) and never had this kind of thing before. It could be a total coincidence, but it seemed only to get like this since I upgraded to Production premium CS6.
I've trauled these forums and others and tried everything people have suggested but nothing works. I have the newest Nvidia drivers, the latest photoshop and production suite updates. I've tried turning off GPU acceleration and I've calibrated my monitors and cintiq several times using the Spyder 3 Elite calibration tools. I've created 8bit, 16bit  and 32bit images and the problem persists no matter what. Other stats:
Adobe Photoshop Version: 13.0.1 (13.0.1 20120808.r.519 2012/08/08:21:00:00) x64
Operating System: Windows 7 64-bit
Video Card: NVIDIA GeForce GTX 280M
Am I missing something here?
This is a 16bit image saved as a jpeg, but still a relatively accurate example of what I see in photoshop. In fact it looks better here. It was created using a low opacity brush with hardness set to zero.
I feel like I've tried everything and I'm pulling my hair out. And help would be gratefully appreciated!
Thank you,
David

Answer 1

Davy-Art wrote:
It's sounding to me like maybe it's normal that there is banding in images created in photoshop, however not normal for me to be able to see it to the extent that I am.
Yes, that sounds correct to me.
Your PSD is only 8-bit, but I see nothing unusual in that file, so if that one looks very obviously banded to you then I expect there is a problem with your system setup.
There is something to be aware of when working in 16-bit mode. If "Cache Levels" in Preferences > Performance is geater than 1 (default is 4, I believe), when the document window zoom is less than about 64%, the calculation of the displayed image is performed with less precision and that can introduce displayed banding which is not really in the document.
I want to show you a distinct benefit of working in 16-bit mode. The following screenshots show 10 applications of a 50% opaque soft brush.
First, done in 8-bit - the banding is horrendous. Second image done in 16-bit (but an 8-bit screenshot, of course) - no obvious banding. Third image is the 16-bit converted to 8-bit by Image > Mode - still looks smooth.