NEX-5N macro help

The easiest way is to use a close-up lens on your kit lens but be sure to choose an achromat and not a cheap single lens. The other alternative as recommended above to use an adapted used macro lens (one you can set the aperture on the lens).

Now I'm quite happy with the quality of my kit lens coupled with a 4dp marumi achromat:

Full resolution crop from it:

Cheers

Marcell