Seem to be having an issue when in whiterun at night it gets steadily darker, while going outside whiterun it starts off dark and gets progressively lighter. This is over a matter of 10-15 seconds, its nothing to do with time moving on. I have been messing around with some mods and thought that realistic lighting may have been the problem but it remains even after removing the mod completely.

I have never noticed this problem before and although today I also updated my catalyst control centre on my graphics card as it had an update, I cant see what they would have done.

Anyone had this before? Are there any files I can reset or is there an easy way to put skyrim back to standard so i can install all of my mods again without losing my saves?