I have read somewhere that if you use AWB, the camera will look for something white and try to compensate and make the area look white in the photo.
I have been using AWB almost 100% of the time...as I dont know how set them correctly. I notice that without changing any camera setting
and shooting at the same place the auto white balance will produce photo with different lightning not sure if exposure play apart in this.
This will be annoying when you want to stitch photo and you notice 5 photos all lights differently but all shooting at same place with same setting.