DX sensor not centred on optical axis of lens

Bet you did not know that ..applies to all Nikon Dx ...here is the proof ......Notice how its nearer the bottom than the top ...now dont argue go test your DX camera same on D7000,D3200,D80

I wonder why?

Well who knows its only a couple of mm BUT if you try to make an old fashioned vinyette or misty edge filter you have to off set it in your lens front mount to get it central ....try liveview to check !!

Just a theory: In most situations light comes from above. In most photos the top is brighter than the bottom. Therefore, the sensor should be a bit closer to the bottom?

so if you rotate your camera to portrait mode ??? No I dont think thats even a theory...more probably some mechanical or lay out advantage....