Blue Tit on high

Well with the excitement of my new Grandson arriving last Evening?And a grey wet morning.I think I was very lucky to get a Blip at all today?
   So here we are with a Blue tit @ the top of a 40 foot Conifer with it's back to me! 
  But at least it shows how good the Nikon D800 is ?
This was shot in DX mode , 4800 x 3200 = 15 mp  and then cropped to 497 x 745 mp! And wow,it's still sharp?