dear all yesterday i used my D700 with my 28-300 and a B&W filter to record this scene. I used Topaz plugin detail 3.0 for Photoshop to enhance the features. I noticed in the skies several rings. Can anyone explain this. i darkened it a bit to get it more prominent
I agree with Len. I used to use ACDsee Pro and encountered this a few times as well -- but I don't remember exactly how, as I have shifted almost exclusively to RAW files editing with CS6. I'd start with the original file and observe carefully as you edit. I think it is safe to say, this is NOT your camera.
I assume that you took original picture in JPG. Since JPG coding handles only 8 bits per colour, you have only 256 levels of each colour. It is quite common that you get pretty distinct bands of a colour in the areas of very subtle tonal changes. This effect is particulary visible when shooting blue sky. When shooting RAW you get more levels of colours and this effect is not so obvious but can still be detected.
When you apply some kind of an edge detection filter to the picture these changes become even more exagerated. You applied Topaz detail filter which detected these subtle tonal changes and produced unpleasant effects along the tonal "isohipses" of the blue sky. Topaz filters are extremely agressive and you have to be very carefull when apllying them since they often produce unwanted and/or unpleasant results.
Try to observe the original picture without any filters applied. Hoover the mouse pointer acros the blue sky and observe the numerical levels of colours (particulary blue) in Photoshop or any other picture editing/viewing programme. You will notice these subtle tonal changes and they will very probably coincide with the "ridges" in your final pictures.
Please let us know whether my theory is correct. If yes, your return info can help many other Nikonians to avoid similar unpleasant effects.
Kind regards, Niko ----------------------- Never underestimate!