D5100 dioptre adjustment question

[Anubis]

I have just received a new D5100. I cannot get sharp focus in the viewfinder no matter how much I adjust the dioptre. It's not my eyes - I use +1 reading glasses, and my other cameras are fine.

Moving the dioptre adjustment does produce very minimal change, but nowhere near focus.

I note that Nikon sell dioptre eyepieces, so my question is, does the camera have a very small range of adjustment, or have a got a faulty camera?

 

[nikon.norm]

Hi Anubis. Try adjusting the dioptre so that you can read the information on the bottom line clearly and sharply in the viewfinder.
If you're using auto focus (and who doesn't) when the camera tells you that the image is in focus it's in focus!