BF109 - Can't we just have the gunsight in the middle?

Yeah, but as we don't have 3D capable game now we have to make the best approximation to reality as possible with a game that tries to represent a 3D environment with only 2 dimensions available.

And as for the aim circle depiction the best compromise with respect to a 2D world and binocular vision simulation is to show the whole aim point circle wobbling slightly around the centre of the screen as long as the right eye is capable to capt the full circle on the reflector glas with all the headshake. So me thinks Lixma got the point at how it should be presented in the game.