Sometimes the spotting is fairly ridiculous with KV. There's been multiples instances where enemy tanks are invisible to me on the open ground and they can keep shooting me and I can't see them(Crew 100%). Latest was in Karelia, where a tiger drove from behind a rock in front of me and started shooting. The only way I know this is because I saw it earlier while it was driving towards the rock and disappeared when it got behind it. When it drove back into my "view" it drove over a tree. I saw the tree fell and then started taking hits to front and eventually got destroyed but never saw the tank.