my d300 is not focusing right.it has never had anything done and i am the second or 3rd owner.do i use Nikon and if so what do i need to do as far as sending it?thank you
You have a choice to send it to Nikon, Authorized Photo Service (http://www.nikoncamerarepair.com), KEH (http://www.keh.com), or any number of other authorized repair shops. Have you tried resetting the camera to factory settings first, and seeing if that fixes it?
If sending to Nikon, all you need to do is go to their service website and fill-out and print the form. You'll be paying for the repairs, so proof of purchase isn't needed.
I recall APS has a similar form on their website, though I've never used them.
Nikon USA will repair EVERYTHING that they feel isn't at 100%, the only say you have is yes or no to the total repair. (IE, if they find a chunk of rubber grip coming off, they will replace it and you will pay even though you may only want the AF issue fixed.)