I have been in an Engineering Electronics shop at a Canadian University for over 20 years, having repaired over one thousand various pieces of equipment.
First question I ask, do you have the manual. Second, have you read the manual. 90% of the time the answer is no. I next get, it's broken.
I find the D7000n to be a very precise piece of electronic equipment. The camera focuses where and how you set it. This camera with the "old 80-400 F4-5.6 lens is the first setup I have had that can accurately get clear shots of the moon.
It can also catch the tiniest object your eye can see. Too many variables to standardize a test for all D7k owners. The OP should read the manual and then come back with better samples of "soft" focus.
I am a gold member because the knowledge one can get from the many informative topics is well worth the money. I spent time reading from the forums. Sorry for the rant.