I think I may have not pointed it out correctly. Alright let me try again. But this time with another picture. Just trying to clarify whether I got a faulty camera or the opposite. :ugh:
This is a full scenery picture, shot using bulb at iso 200, and resized at maximum quality: (picture was taken during sunrise)
This is the part of the "dark grainy + pixelated?" area:
Meanwhile, this is the clear sky :
Sorry guys if I'm not making any sense here. But if there's nothing wrong by your side or maybe this is a normal thing, then I'm sure it's either my screen display is causing me to see weird stuff or I may have to declare myself as an inexperienced photographer. But a big thanks for the really fast reply