Please help me with focussing - D7000

[philstanbridge]

I'm new to the D7000 and am loving it. But I generally find focussing quite difficult. I tend to use Aperture Priority mode with Auto ISO (sensitivity set at 1600 max). I take mostly portraits at the moment with my 35mm 1.8G and although the focus point of my photos are usually pin sharp there are parts that seem totally out of focus. It's these parts that I want to get in line with the rest of the portrait. I also like to blur the background so I can focus purely on the subject.

I've tried different things and settings including all the autofocus modes and the focus points etc etc. I'm happy to experiment of course.

Any suggestions?

 

[philstanbridge]

I tend to use low f-stops, the 1.8 looks fab to be honest but I've noticed slightly higher f-stops produce sharper images but not necessarily the parts I want in focuse - is this right or is it my eyesight?

By the way, my subject is my nearly 2 year old son who is always on the move, so I have my work cut out.

 

[philstanbridge]

Here is probably my best photograph to date. In terms of sharpness I'm dead happy with that as it focusses on his face, with enough of the background blurred. This was a 2.8 f-stop and 560 ISO according to FlickR.

But this was a bit of a fluke. I've tried to get similar results using different lighting and such like, with out the same success. Ironically the D7000 seems to perform better in lower light than in natural or lighter conditions! Maybe it's just me.