Whenever i take photos outside in iA mode or practically any mode the shutter speed instanly goes to 1/1600 and iso of 80, its mainly when im trying to take pictures of scenery with sky and clouds in it, and then the photo that it takes is completely white, sometimes with a faint brownish outline of things like trees. Does anyone know how i can fix this, all awnsers are much appreciated

Thankyou.