When moving my joystick fast, in some area specially outside during the day, it goes very dark to light when looking to mountain or an outside door for exemple... Is it a bug ?

I notice that as well, I think it may be an effect of the players eyes adjusting to the light. I like it
(I think we are talking about the same thing)

Yes this, its annoying, not sure its intended

And it is definitly outside only. Tested inside no light/shadow change when moving quick

thats your eyes adjusting to the light it looks awesome in my opinion.......its like in real life go inside when out in the sun and everything will look dark.. the eyes adjust and then they let more light in

Yeah but when i turn my head in real life , my field of view doesnt go dark/and light when moving... I think the effect is yay to much in skyrim