Howdy Darrylx444 and thanks. atm my smoothness is at 50, it was at 0 but am backing it down in increments of 5 until I find what works.
I don't see any artifacts, but truthfully, I'm not sure I have the IR5 camera in the correct position. Currently it's (on a Asus 27" IPS monitor) approx. 2"/5cm left of center. In the camera view the middle green node is dead center, however, the nodes move further to the right than to the left when moving through the range, (edge-to-edge of the monitor).
I saw your photo in your next post and will verify the settings again, but will also try your saturation setting. I think your ideas are narrowing things down to the culprit, thanks.