Please check the post below. I added a link to a youtube video and Brian Tutorial on how to get rid of them.
Some more info:
-I have a D7200 too, and works great!!! I shoot in RAW only. What you describe as using f9 will help you to avoid vignetting, but not halos.
-Halos appear as a result of modifying brightness, contrast, shadows, etc. in your post software, especially when abusing them. So you have 2 options:
1. Work separate layers in Photoshop. One for the AC and another for the background (sky). This is if absolutely you need to use brightness/contrast/etc to adjust your picture. Brian's tutorial is all about this.
2. Use this method:
1.Exposing correctly the picture (we knew that

2.Cropping and correcting white balance in Lightroom (or PS sure) and then modifying contrast and light in Photoshop BY USING THE CURVES tool. No halos!!! just a bunch of dust spots that need clean up anyway. The curves tool is the cleanest way unless of course yo go too far.
I hope this helps.
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